diff --git a/CMakeLists.txt b/CMakeLists.txt
index 94863fd3..9aa6a1af 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -32,7 +32,7 @@ config_h_add_compile_definitions(BUILD="${CMAKE_HOST_SYSTEM_PROCESSOR}-${CMAKE_H
 config_h_add_compile_definitions(TARGET="${CMAKE_SYSTEM_PROCESSOR}-${CMAKE_SYSTEM}-${CMAKE_CXX_COMPILER_TARGET}")
 
 if(WIN32)
-  set(CMAKE_CXX_FLAGS ${CMAKE_CXX_FLAGS} -D_POSIX_C_SOURCE=1)
+  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -D_POSIX_C_SOURCE=1")
   set(CMAKE_EXE_LINKER_FLAGS ${CMAKE_EXE_LINKER_FLAGS} -Wl,--dynamicbase -Wl,--nxcompat)
   set(CMAKE_SHARED_LINKER_FLAGS ${CMAKE_SHARED_LINKER_FLAGS} -Wl,--dynamicbase -Wl,--nxcompat)
   set(CMAKE_STATIC_LINKER_FLAGS_LINKER_FLAGS ${CMAKE_STATIC_LINKER_FLAGS} -Wl,--dynamicbase -Wl,--nxcompat)
@@ -79,6 +79,16 @@ elseif(CMAKE_CXX_COMPILER_ID STREQUAL "Intel")
 # using Intel C++
 elseif(CMAKE_CXX_COMPILER_ID STREQUAL "MSVC")
   # using Visual Studio C++
+  # config_h_add_compile_definitions(__MSVC__=1) # USE _MSC_VER
+  add_compile_definitions(NOMINMAX)
+  config_h_add_compile_macro("__restrict__ __restrict") 
+  config_h_add_compile_macro("__attribute__(unused) /*Empty*/")
+endif()
+
+if(WIN32 AND NOT MINGW)
+  set(NO_UNIX)
+  config_h_add_compile_macro("mode_t int")
+  config_h_add_compile_definitions(NO_UNIX=1)
 endif()
 
 if(CMAKE_C_COMPILER_ID STREQUAL "GNU")
@@ -350,6 +360,8 @@ if(WITH_OPENSSL)
 
   if(OPENSSL_FOUND AND NOT HAVE_SSL)
     set(HAVE_OPENSSL yes CACHE BOOL "Define is you have openssl" FORCE)
+    set(OPENSSL_CFLAGS "")
+    set(OPENSSL_LIBS ${OPENSSL_LIBRARIES})
     config_h_add_compile_definitions(HAVE_OPENSSL=1)
 
     set(save_CMAKE_REQUIRED_LIBRARIES ${CMAKE_REQUIRED_LIBRARIES})
diff --git a/cmake/GenerateConfigH.cmake b/cmake/GenerateConfigH.cmake
index 45b5ef79..e73f8db9 100644
--- a/cmake/GenerateConfigH.cmake
+++ b/cmake/GenerateConfigH.cmake
@@ -2,6 +2,10 @@ function(config_h_add_compile_definitions definitions)
     set(${PROJECT_NAME}_CONFIG_H_definitions ${${PROJECT_NAME}_CONFIG_H_definitions} ${definitions} PARENT_SCOPE)
 endfunction()
 
+function(config_h_add_compile_macro definitions)
+    set(${PROJECT_NAME}_CONFIG_H_macros ${${PROJECT_NAME}_CONFIG_H_macros} ${definitions} PARENT_SCOPE)
+endfunction()
+
 function(config_h_generate_header name)
     write_file(${CMAKE_CURRENT_BINARY_DIR}/${name}.h.cmake.in "/* config.h.in.  Generated from cmake*/\n")
     foreach(def ${${PROJECT_NAME}_CONFIG_H_definitions})
@@ -18,5 +22,10 @@ function(config_h_generate_header name)
         endif()
         write_file(${CMAKE_CURRENT_BINARY_DIR}/${name}.h.cmake.in "#define ${def_name} @${def_name}_config_h_val@\n" APPEND)
     endforeach()
+
+    foreach(macro ${${PROJECT_NAME}_CONFIG_H_macros})
+        write_file(${CMAKE_CURRENT_BINARY_DIR}/${name}.h.cmake.in "#define ${macro} \n" APPEND)
+    endforeach()
+
     configure_file(${CMAKE_CURRENT_BINARY_DIR}/${name}.h.cmake.in ${name}.h)
 endfunction()
\ No newline at end of file
diff --git a/deps/wslay/CMakeLists.txt b/deps/wslay/CMakeLists.txt
index 0c741a91..593799b5 100644
--- a/deps/wslay/CMakeLists.txt
+++ b/deps/wslay/CMakeLists.txt
@@ -33,6 +33,27 @@ include(CheckIncludeFiles)
 include(CheckTypeSize)
 include(CheckFunctionExists)
 
+if(CMAKE_CXX_COMPILER_ID STREQUAL "Clang")
+# using Clang
+elseif(CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
+  # using GCC
+  set(CMAKE_CXX_FLAGS ${CMAKE_CXX_FLAGS} -pipe)
+
+elseif(CMAKE_CXX_COMPILER_ID STREQUAL "Intel")
+# using Intel C++
+elseif(CMAKE_CXX_COMPILER_ID STREQUAL "MSVC")
+  # using Visual Studio C++
+  # config_h_add_compile_definitions(__MSVC__=1) # USE _MSC_VER
+  add_compile_definitions(NOMINMAX)
+  config_h_add_compile_macro("__restrict__ __restrict") 
+  config_h_add_compile_macro("__attribute__(unused) /*Empty*/")
+endif()
+
+if(WIN32 AND NOT MINGW)
+  set(NO_UNIX)
+  config_h_add_compile_definitions(NO_UNIX=1)
+endif()
+
 
 if(ENABLE_WERROR)
     add_compile_options(-Wall -Werror -Wformat-security)
diff --git a/deps/wslay/examples/echoserv.cc b/deps/wslay/examples/echoserv.cc
index 48e5d3f1..70fcf631 100644
--- a/deps/wslay/examples/echoserv.cc
+++ b/deps/wslay/examples/echoserv.cc
@@ -27,6 +27,7 @@
 // g++ -Wall -O2 -g -o echoserv echoserv.cc -L../lib/.libs -I../lib/includes -lwslay -lnettle
 // $ export LD_LIBRARY_PATH=../lib/.libs
 // $ ./a.out 9000
+
 #include <sys/types.h>
 #include <sys/socket.h>
 #include <netdb.h>
diff --git a/deps/wslay/examples/fork-echoserv.c b/deps/wslay/examples/fork-echoserv.c
index 3f2b2a00..fc21e5a7 100644
--- a/deps/wslay/examples/fork-echoserv.c
+++ b/deps/wslay/examples/fork-echoserv.c
@@ -35,6 +35,9 @@
  * $ export LD_LIBRARY_PATH=../lib/.libs
  * $ ./a.out 9000
  */
+
+#include "config.h"
+
 #include <sys/types.h>
 #include <sys/socket.h>
 #include <netdb.h>
diff --git a/deps/wslay/examples/testclient.cc b/deps/wslay/examples/testclient.cc
index 03ce0240..63262db2 100644
--- a/deps/wslay/examples/testclient.cc
+++ b/deps/wslay/examples/testclient.cc
@@ -26,6 +26,9 @@
 // $ g++ -Wall -O2 -g -o testclient testclient.cc -L../lib/.libs -I../lib/includes -lwslay -lnettle
 // $ export LD_LIBRARY_PATH=../lib/.libs
 // $ ./a.out localhost 9001
+
+#include "config.h"
+
 #include <sys/types.h>
 #include <sys/socket.h>
 #include <netdb.h>
diff --git a/deps/wslay/lib/includes/wslay/wslay.h b/deps/wslay/lib/includes/wslay/wslay.h
index 77a4e825..d7ed2c67 100644
--- a/deps/wslay/lib/includes/wslay/wslay.h
+++ b/deps/wslay/lib/includes/wslay/wslay.h
@@ -33,6 +33,11 @@ extern "C" {
 #include <stdlib.h>
 #include <sys/types.h>
 
+#if defined(_MSC_VER)
+#include <BaseTsd.h>
+typedef SSIZE_T ssize_t;
+#endif
+
 /*
  * wslay/wslayver.h is generated from wslay/wslayver.h.in by
  * configure. The projects which do not use autotools can set
diff --git a/src/AbstractDiskWriter.cc b/src/AbstractDiskWriter.cc
index 52efc012..0bd84248 100644
--- a/src/AbstractDiskWriter.cc
+++ b/src/AbstractDiskWriter.cc
@@ -34,7 +34,9 @@
 /* copyright --> */
 #include "AbstractDiskWriter.h"
 
-#include <unistd.h>
+#ifndef NO_UNIX
+#  include <unistd.h>
+#endif
 #ifdef HAVE_MMAP
 #  include <sys/mman.h>
 #endif // HAVE_MMAP
@@ -54,12 +56,16 @@
 #include "error_code.h"
 #include "LogFactory.h"
 
+#if defined(_MSC_VER)
+#  include <winioctl.h>
+#endif
+
 namespace aria2 {
 
 AbstractDiskWriter::AbstractDiskWriter(const std::string& filename)
     : filename_(filename),
       fd_(A2_BAD_FD),
-#ifdef __MINGW32__
+#if defined(__MINGW32__) || defined(_MSC_VER)
       mapView_(0),
 #else  // !__MINGW32__
 #endif // !__MINGW32__
@@ -78,7 +84,7 @@ namespace {
 // the value of GetLastError(). Otherwise, return errno.
 int fileError()
 {
-#ifdef __MINGW32__
+#if defined(__MINGW32__) || defined(_MSC_VER)
   return GetLastError();
 #else  // !__MINGW32__
   return errno;
@@ -92,7 +98,7 @@ namespace {
 // errno.
 std::string fileStrerror(int errNum)
 {
-#ifdef __MINGW32__
+#if defined(__MINGW32__) || defined(_MSC_VER)
   auto msg = util::formatLastError(errNum);
   if (msg.empty()) {
     char buf[256];
@@ -113,7 +119,7 @@ void AbstractDiskWriter::openFile(int64_t totalLength)
   }
   catch (RecoverableException& e) {
     if (
-#ifdef __MINGW32__
+#if defined(__MINGW32__) || defined(_MSC_VER)
         e.getErrNum() == ERROR_FILE_NOT_FOUND ||
         e.getErrNum() == ERROR_PATH_NOT_FOUND
 #else  // !__MINGW32__
@@ -133,7 +139,7 @@ void AbstractDiskWriter::closeFile()
 #if defined(HAVE_MMAP) || defined(__MINGW32__)
   if (mapaddr_) {
     int errNum = 0;
-#  ifdef __MINGW32__
+#  if defined(__MINGW32__) || defined(_MSC_VER)
     if (!UnmapViewOfFile(mapaddr_)) {
       errNum = GetLastError();
     }
@@ -157,7 +163,7 @@ void AbstractDiskWriter::closeFile()
   }
 #endif // HAVE_MMAP || defined __MINGW32__
   if (fd_ != A2_BAD_FD) {
-#ifdef __MINGW32__
+#if defined(__MINGW32__) || defined(_MSC_VER)
     CloseHandle(fd_);
 #else  // !__MINGW32__
     close(fd_);
@@ -167,7 +173,7 @@ void AbstractDiskWriter::closeFile()
 }
 
 namespace {
-#ifdef __MINGW32__
+#if defined(__MINGW32__) || defined(_MSC_VER)
 HANDLE openFileWithFlags(const std::string& filename, int flags,
                          error_code::Value errCode)
 {
@@ -265,7 +271,7 @@ ssize_t AbstractDiskWriter::writeDataInternal(const unsigned char* data,
     ssize_t writtenLength = 0;
     seek(offset);
     while ((size_t)writtenLength < len) {
-#ifdef __MINGW32__
+#if defined(__MINGW32__) || defined(_MSC_VER)
       DWORD nwrite;
       if (WriteFile(fd_, data + writtenLength, len - writtenLength, &nwrite,
                     0)) {
@@ -303,7 +309,7 @@ ssize_t AbstractDiskWriter::readDataInternal(unsigned char* data, size_t len,
   }
   else {
     seek(offset);
-#ifdef __MINGW32__
+#if defined(__MINGW32__) || defined(_MSC_VER)
     DWORD nread;
     if (ReadFile(fd_, data, len, &nread, 0)) {
       return nread;
@@ -323,7 +329,7 @@ ssize_t AbstractDiskWriter::readDataInternal(unsigned char* data, size_t len,
 void AbstractDiskWriter::seek(int64_t offset)
 {
   assert(offset >= 0);
-#ifdef __MINGW32__
+#if defined(__MINGW32__) || defined(_MSC_VER)
   LARGE_INTEGER fileLength;
   fileLength.QuadPart = offset;
   if (SetFilePointerEx(fd_, fileLength, 0, FILE_BEGIN) == 0)
@@ -345,7 +351,7 @@ void AbstractDiskWriter::ensureMmapWrite(size_t len, int64_t offset)
     if (mapaddr_) {
       if (static_cast<int64_t>(len + offset) > maplen_) {
         int errNum = 0;
-#  ifdef __MINGW32__
+#  if defined(__MINGW32__) || defined(_MSC_VER)
         if (!UnmapViewOfFile(mapaddr_)) {
           errNum = GetLastError();
         }
@@ -385,7 +391,7 @@ void AbstractDiskWriter::ensureMmapWrite(size_t len, int64_t offset)
 
       int errNum = 0;
       if (static_cast<int64_t>(len + offset) <= filesize) {
-#  ifdef __MINGW32__
+#  if defined(__MINGW32__) || defined(_MSC_VER)
         mapView_ = CreateFileMapping(fd_, 0, PAGE_READWRITE, filesize >> 32,
                                      filesize & 0xffffffffu, 0);
         if (mapView_) {
@@ -432,7 +438,7 @@ namespace {
 bool isDiskFullError(int errNum)
 {
   return
-#ifdef __MINGW32__
+#if defined(__MINGW32__) || defined(_MSC_VER)
       errNum == ERROR_DISK_FULL || errNum == ERROR_HANDLE_DISK_FULL
 #else  // !__MINGW32__
       errNum == ENOSPC
@@ -483,7 +489,7 @@ void AbstractDiskWriter::truncate(int64_t length)
   if (fd_ == A2_BAD_FD) {
     throw DL_ABORT_EX("File not yet opened.");
   }
-#ifdef __MINGW32__
+#if defined(__MINGW32__) || defined(_MSC_VER)
   // Since mingw32's ftruncate cannot handle over 2GB files, we use
   // SetEndOfFile instead.
   seek(length);
@@ -505,7 +511,7 @@ void AbstractDiskWriter::allocate(int64_t offset, int64_t length, bool sparse)
     throw DL_ABORT_EX("File not yet opened.");
   }
   if (sparse) {
-#ifdef __MINGW32__
+#if defined(__MINGW32__) || defined(_MSC_VER)
     DWORD bytesReturned;
     if (!DeviceIoControl(fd_, FSCTL_SET_SPARSE, 0, 0, 0, 0, &bytesReturned,
                          0)) {
@@ -517,7 +523,7 @@ void AbstractDiskWriter::allocate(int64_t offset, int64_t length, bool sparse)
     return;
   }
 #ifdef HAVE_SOME_FALLOCATE
-#  ifdef __MINGW32__
+#  if defined(__MINGW32__) || defined(_MSC_VER)
   truncate(offset + length);
   if (!SetFileValidData(fd_, offset + length)) {
     auto errNum = fileError();
@@ -595,7 +601,7 @@ void AbstractDiskWriter::flushOSBuffers()
   if (fd_ == A2_BAD_FD) {
     return;
   }
-#ifdef __MINGW32__
+#if defined(__MINGW32__) || defined(_MSC_VER)
   FlushFileBuffers(fd_);
 #else  // !__MINGW32__
   fsync(fd_);
diff --git a/src/AbstractDiskWriter.h b/src/AbstractDiskWriter.h
index 96518a68..ed50ea7c 100644
--- a/src/AbstractDiskWriter.h
+++ b/src/AbstractDiskWriter.h
@@ -44,7 +44,7 @@ class AbstractDiskWriter : public DiskWriter {
 private:
   std::string filename_;
 
-#ifdef __MINGW32__
+#if defined(__MINGW32__) || defined(_MSC_VER)
   HANDLE fd_;
   // The handle for memory mapped file. mmap equivalent in Windows.
   HANDLE mapView_;
diff --git a/src/BinaryStream.h b/src/BinaryStream.h
index 8b442475..77bd4cb3 100644
--- a/src/BinaryStream.h
+++ b/src/BinaryStream.h
@@ -37,7 +37,9 @@
 
 #include "common.h"
 
-#include <unistd.h>
+#ifndef NO_UNIX
+#  include <unistd.h>
+#endif
 
 namespace aria2 {
 
diff --git a/src/BtFileAllocationEntry.cc b/src/BtFileAllocationEntry.cc
index 8ef15265..5a8dea06 100644
--- a/src/BtFileAllocationEntry.cc
+++ b/src/BtFileAllocationEntry.cc
@@ -92,7 +92,7 @@ void BtFileAllocationEntry::prepareForNextAction(
     }
   }
   else {
-#ifdef __MINGW32__
+#if defined(__MINGW32__) || defined(_MSC_VER)
     if (!diskAdaptor->isReadOnlyEnabled()) {
       // On Windows, if aria2 opens files with GENERIC_WRITE access
       // right, some programs cannot open them aria2 is seeding. To
diff --git a/src/BufferedFile.cc b/src/BufferedFile.cc
index 0f9a97b6..6384eb8f 100644
--- a/src/BufferedFile.cc
+++ b/src/BufferedFile.cc
@@ -47,7 +47,7 @@ BufferedFile::BufferedFile(const char* filename, const char* mode)
     : fp_(strcmp(DEV_STDIN, filename) == 0
               ? stdin
               :
-#ifdef __MINGW32__
+#if defined(__MINGW32__) || defined(_MSC_VER)
               a2fopen(utf8ToWChar(filename).c_str(), utf8ToWChar(mode).c_str())
 #else  // !__MINGW32__
               a2fopen(filename, mode)
@@ -81,7 +81,7 @@ int BufferedFile::onClose()
   int rv = 0;
   if (fp_) {
     fflush(fp_);
-#ifndef __MINGW32__
+#if defined(__MINGW32__) || defined(_MSC_VER)
     fsync(fileno(fp_));
 #else  // __MINGW32__
     _commit(fileno(fp_));
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index e30dd61b..dcf31a8f 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -1282,6 +1282,7 @@ target_include_directories(aria2 INTERFACE ${CMAKE_CURRENT_SOURCE_DIR}/includes)
 
 if(HAVE_ZLIB)
   target_include_directories(aria2 PUBLIC ${ZLIB_INCLUDE_DIRS})
+  target_include_directories(main PUBLIC ${LIBXML2_INCLUDE_DIR})
   target_link_libraries(aria2 ZLIB::ZLIB)
 endif()
 
@@ -1292,16 +1293,19 @@ endif()
 
 if(HAVE_LIBXML2)
   target_include_directories(aria2 PUBLIC ${LIBXML2_INCLUDE_DIR})
+  target_include_directories(main PUBLIC ${LIBXML2_INCLUDE_DIR})
   target_link_libraries(aria2 LibXml2::LibXml2)
 endif()
 
 if(HAVE_LIBEXPAT)
   target_include_directories(aria2 PUBLIC ${EXPAT_INCLUDE_DIRS})
+  target_include_directories(main PUBLIC ${EXPAT_INCLUDE_DIRS})
   target_link_libraries(aria2 EXPAT::EXPAT)
 endif()
 
 if(HAVE_SQLITE3)
   target_include_directories(aria2 PUBLIC ${SQLite3_INCLUDE_DIRS})
+  target_include_directories(main PUBLIC ${SQLite3_INCLUDE_DIRS})
   target_link_libraries(aria2 SQLite::SQLite3)
 endif()
 
@@ -1316,11 +1320,15 @@ endif()
 if(HAVE_LIBGNUTLS)
   target_include_directories(aria2 PUBLIC ${GNUTLS_INCLUDE_DIR})
   target_compile_definitions(aria2 PUBLIC ${LIBGNUTLS_CFLAGS})
+  target_include_directories(main PUBLIC ${GNUTLS_INCLUDE_DIR})
+  target_compile_definitions(main PUBLIC ${LIBGNUTLS_CFLAGS})
   target_link_libraries(aria2 GnuTLS::GnuTLS)
 endif()
 
 if(HAVE_OPENSSL)
   target_include_directories(aria2 PUBLIC ${OPENSSL_INCLUDE_DIR})
+  target_include_directories(main PUBLIC ${OPENSSL_INCLUDE_DIR})
+
   target_link_libraries(aria2 OpenSSL::SSL)
 
   # target_link_libraries(aria2 INTERFACE OpenSSL::Crypto)
@@ -1328,21 +1336,25 @@ endif()
 
 if(HAVE_LIBNETTLE)
   target_include_directories(aria2 PUBLIC ${NETTLE_INCLUDE_DIR})
+  target_include_directories(main PUBLIC ${NETTLE_INCLUDE_DIR})
   target_link_libraries(aria2 Nettle::Nettle)
 endif()
 
 if(HAVE_LIBGMP)
   target_include_directories(aria2 PUBLIC ${GMP_INCLUDE_DIR})
+  target_include_directories(main PUBLIC ${GMP_INCLUDE_DIR})
   target_link_libraries(aria2 GMP::GMP)
 endif()
 
 if(HAVE_LIBGCRYPT)
   target_include_directories(aria2 PUBLIC ${LibGcrypt_INCLUDE_DIR})
+  target_include_directories(main PUBLIC ${LibGcrypt_INCLUDE_DIR})
   target_link_libraries(aria2 LibGcrypt::LibGcrypt)
 endif()
 
 if(HAVE_LIBSSH2)
   target_include_directories(aria2 PUBLIC ${LIBSSH2_INCLUDE_DIR})
+  target_include_directories(main PUBLIC ${LIBSSH2_INCLUDE_DIR})
   target_link_libraries(aria2 LibSSH2::LibSSH2)
 endif()
 
@@ -1353,6 +1365,7 @@ endif()
 
 if(ENABLE_WEBSOCKET)
   target_include_directories(aria2 PUBLIC ${WSLAY_INCLUDE_DIR})
+  target_include_directories(main PUBLIC ${WSLAY_INCLUDE_DIR})
   target_link_libraries(aria2 wslay)
 endif()
 
diff --git a/src/ConsoleStatCalc.cc b/src/ConsoleStatCalc.cc
index a28a4a54..343f7d37 100644
--- a/src/ConsoleStatCalc.cc
+++ b/src/ConsoleStatCalc.cc
@@ -40,7 +40,9 @@
 #ifdef HAVE_SYS_IOCTL_H
 #  include <sys/ioctl.h>
 #endif // HAVE_SYS_IOCTL_H
-#include <unistd.h>
+#ifndef NO_UNIX
+#  include <unistd.h>
+#endif
 
 #include <cstdio>
 #include <iomanip>
@@ -272,7 +274,7 @@ ConsoleStatCalc::ConsoleStatCalc(std::chrono::seconds summaryInterval,
     : summaryInterval_(std::move(summaryInterval)),
       readoutVisibility_(true),
       truncate_(true),
-#ifdef __MINGW32__
+#if defined(__MINGW32__) || defined(_MSC_VER)
       isTTY_(true),
 #else  // !__MINGW32__
       isTTY_(isatty(STDOUT_FILENO) == 1),
@@ -301,7 +303,7 @@ void ConsoleStatCalc::calculateStat(const DownloadEngine* e)
   unsigned short int cols = 79;
 
   if (isTTY_) {
-#ifndef __MINGW32__
+#if efined(__MINGW32__) || defined(_MSC_VER)
 #  ifdef HAVE_TERMIOS_H
     struct winsize size;
     if (ioctl(STDOUT_FILENO, TIOCGWINSZ, &size) == 0) {
diff --git a/src/Context.cc b/src/Context.cc
index d12775bb..ffa8f5b7 100644
--- a/src/Context.cc
+++ b/src/Context.cc
@@ -34,7 +34,9 @@
 /* copyright --> */
 #include "Context.h"
 
-#include <unistd.h>
+#ifndef NO_UNIX
+#  include <unistd.h>
+#endif
 #include <getopt.h>
 
 #ifdef HAVE_SYS_RESOURCE_H
diff --git a/src/DefaultPieceStorage.cc b/src/DefaultPieceStorage.cc
index e08b1b18..f7d7ce2d 100644
--- a/src/DefaultPieceStorage.cc
+++ b/src/DefaultPieceStorage.cc
@@ -485,7 +485,7 @@ void DefaultPieceStorage::completePiece(const std::shared_ptr<Piece>& piece)
 #ifdef ENABLE_BITTORRENT
     if (downloadContext_->hasAttribute(CTX_ATTR_BT)) {
       if (!bittorrent::getTorrentAttrs(downloadContext_)->metadata.empty()) {
-#  ifdef __MINGW32__
+#  if defined(__MINGW32__) || defined(_MSC_VER)
         // On Windows, if aria2 opens files with GENERIC_WRITE access
         // right, some programs cannot open them aria2 is seeding. To
         // avoid this situation, re-open the files with read-only
diff --git a/src/DownloadCommand.h b/src/DownloadCommand.h
index aeee4416..e4ccad41 100644
--- a/src/DownloadCommand.h
+++ b/src/DownloadCommand.h
@@ -37,7 +37,9 @@
 
 #include "AbstractCommand.h"
 
-#include <unistd.h>
+#ifndef NO_UNIX
+#  include <unistd.h>
+#endif
 
 namespace aria2 {
 
diff --git a/src/FeatureConfig.cc b/src/FeatureConfig.cc
index 2b43c8b1..75f78a44 100644
--- a/src/FeatureConfig.cc
+++ b/src/FeatureConfig.cc
@@ -273,7 +273,7 @@ std::string usedCompilerAndPlatform()
 
 #elif defined(__GNUG__)
 
-#  ifdef __MINGW32__
+#  if defined(__MINGW32__) || defined(_MSC_VER)
   rv << "mingw ";
 #    ifdef __MINGW32_MAJOR_VERSION
   rv << (int)__MINGW32_MAJOR_VERSION;
diff --git a/src/File.cc b/src/File.cc
index a98dca61..4faf8cae 100644
--- a/src/File.cc
+++ b/src/File.cc
@@ -39,7 +39,9 @@
 #ifdef HAVE_UTIME_H
 #  include <utime.h>
 #endif // HAVE_UTIME_H
-#include <unistd.h>
+#ifndef NO_UNIX
+#  include <unistd.h>
+#endif
 
 #include <vector>
 #include <cstring>
@@ -120,7 +122,7 @@ bool File::remove()
   }
 }
 
-#ifdef __MINGW32__
+#if defined(__MINGW32__) || defined(_MSC_VER)
 namespace {
 HANDLE openFile(const std::string& filename, bool readOnly = true)
 {
@@ -136,7 +138,7 @@ HANDLE openFile(const std::string& filename, bool readOnly = true)
 
 int64_t File::size()
 {
-#ifdef __MINGW32__
+#if defined(__MINGW32__) || defined(_MSC_VER)
   // _wstat cannot be used for symlink.  It always returns 0.  Quoted
   // from https://msdn.microsoft.com/en-us/library/14h5k7ff.aspx:
   //
@@ -165,7 +167,7 @@ bool File::mkdirs()
   if (isDir()) {
     return false;
   }
-#ifdef __MINGW32__
+#if defined(__MINGW32__) || defined(_MSC_VER)
   std::string path = name_;
   for (std::string::iterator i = path.begin(), eoi = path.end(); i != eoi;
        ++i) {
@@ -224,7 +226,7 @@ bool File::mkdirs()
     if (i != end) {
       ++i;
     }
-#ifdef __MINGW32__
+#if defined(__MINGW32__) || defined(_MSC_VER)
     if (*(j - 1) == ':') {
       // This is a drive letter, e.g. C:, so skip it.
       continue;
@@ -289,7 +291,7 @@ bool File::isDir(const std::string& filename) { return File(filename).isDir(); }
 
 bool File::renameTo(const std::string& dest)
 {
-#ifdef __MINGW32__
+#if defined(__MINGW32__) || defined(_MSC_VER)
   // MinGW's rename() doesn't delete an existing destination.  Better
   // to use MoveFileEx, which usually provides atomic move in aria2
   // usecase.
@@ -374,7 +376,7 @@ Time File::getModifiedTime()
 
 std::string File::getCurrentDir()
 {
-#ifdef __MINGW32__
+#if defined(__MINGW32__) || defined(_MSC_VER)
   const size_t buflen = 2048;
   wchar_t buf[buflen];
   if (_wgetcwd(buf, buflen)) {
@@ -397,7 +399,7 @@ std::string File::getCurrentDir()
 
 const char* File::getPathSeparators()
 {
-#ifdef __MINGW32__
+#if defined(__MINGW32__) || defined(_MSC_VER)
   return "/\\";
 #else  // !__MINGW32__
   return "/";
diff --git a/src/FileAllocationIterator.h b/src/FileAllocationIterator.h
index d4aeb1a7..2ac821f4 100644
--- a/src/FileAllocationIterator.h
+++ b/src/FileAllocationIterator.h
@@ -37,7 +37,9 @@
 
 #include "common.h"
 
-#include <unistd.h>
+#ifndef NO_UNIX
+#  include <unistd.h>
+#endif
 
 namespace aria2 {
 
diff --git a/src/FtpConnection.cc b/src/FtpConnection.cc
index 0893d294..75bc49ec 100644
--- a/src/FtpConnection.cc
+++ b/src/FtpConnection.cc
@@ -368,7 +368,7 @@ int FtpConnection::receiveResponse()
   }
 }
 
-#ifdef __MINGW32__
+#if defined(__MINGW32__) || defined(_MSC_VER)
 #  define LONGLONG_PRINTF "%I64d"
 #  define ULONGLONG_PRINTF "%I64u"
 #  define LONGLONG_SCANF "%I64d"
diff --git a/src/GZipFile.cc b/src/GZipFile.cc
index 80ef10ee..b85665d8 100644
--- a/src/GZipFile.cc
+++ b/src/GZipFile.cc
@@ -50,7 +50,7 @@ GZipFile::GZipFile(const char* filename, const char* mode)
       strcmp(DEV_STDIN, filename) == 0
           ? stdin
           :
-#ifdef __MINGW32__
+#if defined(__MINGW32__) || defined(_MSC_VER)
           a2fopen(utf8ToWChar(filename).c_str(), utf8ToWChar(mode).c_str())
 #else  // !__MINGW32__
           a2fopen(filename, mode)
diff --git a/src/IteratableValidator.h b/src/IteratableValidator.h
index dcd52b8d..340c643b 100644
--- a/src/IteratableValidator.h
+++ b/src/IteratableValidator.h
@@ -37,7 +37,9 @@
 
 #include "common.h"
 
-#include <unistd.h>
+#ifndef NO_UNIX
+#  include <unistd.h>
+#endif
 
 namespace aria2 {
 
diff --git a/src/LibuvEventPoll.cc b/src/LibuvEventPoll.cc
index 1b0b549d..9a90e97f 100644
--- a/src/LibuvEventPoll.cc
+++ b/src/LibuvEventPoll.cc
@@ -34,7 +34,7 @@
  */
 /* copyright --> */
 
-#ifdef __MINGW32__
+#if defined(__MINGW32__) || defined(_MSC_VER)
 #  ifdef _WIN32_WINNT
 #    undef _WIN32_WINNT
 #  endif // _WIN32_WINNT
diff --git a/src/Logger.cc b/src/Logger.cc
index 87168e16..825a524c 100644
--- a/src/Logger.cc
+++ b/src/Logger.cc
@@ -34,7 +34,9 @@
 /* copyright --> */
 #include "Logger.h"
 
-#include <unistd.h>
+#ifndef NO_UNIX
+#  include <unistd.h>
+#endif
 #include <cstring>
 #include <cstdio>
 #include <cassert>
diff --git a/src/LpdMessageReceiver.cc b/src/LpdMessageReceiver.cc
index a74b33b7..cceb7584 100644
--- a/src/LpdMessageReceiver.cc
+++ b/src/LpdMessageReceiver.cc
@@ -59,7 +59,7 @@ bool LpdMessageReceiver::init(const std::string& localAddr)
 {
   try {
     socket_ = std::make_shared<SocketCore>(SOCK_DGRAM);
-#ifdef __MINGW32__
+#if defined(__MINGW32__) || defined(_MSC_VER)
     // Binding multicast address fails under Windows.
     socket_->bindWithFamily(multicastPort_, AF_INET);
 #else  // !__MINGW32__
diff --git a/src/MultiUrlRequestInfo.cc b/src/MultiUrlRequestInfo.cc
index 833188e3..64027e1a 100644
--- a/src/MultiUrlRequestInfo.cc
+++ b/src/MultiUrlRequestInfo.cc
@@ -231,7 +231,7 @@ int MultiUrlRequestInfo::prepare()
     auto authConfigFactory = make_unique<AuthConfigFactory>();
     File netrccf(option_->get(PREF_NETRC_PATH));
     if (!option_->getAsBool(PREF_NO_NETRC) && netrccf.isFile()) {
-#ifdef __MINGW32__
+#if defined(__MINGW32__) || defined(_MSC_VER)
       // Windows OS does not have permission, so set it to 0.
       mode_t mode = 0;
 #else  // !__MINGW32__
diff --git a/src/OptionParser.cc b/src/OptionParser.cc
index 75d0885f..b4a66e75 100644
--- a/src/OptionParser.cc
+++ b/src/OptionParser.cc
@@ -34,7 +34,9 @@
 /* copyright --> */
 #include "OptionParser.h"
 
-#include <unistd.h>
+#ifndef NO_UNIX
+#  include <unistd.h>
+#endif
 #include <getopt.h>
 
 #include <cstring>
diff --git a/src/PeerConnection.h b/src/PeerConnection.h
index 17e023f0..93198a47 100644
--- a/src/PeerConnection.h
+++ b/src/PeerConnection.h
@@ -37,7 +37,9 @@
 
 #include "common.h"
 
-#include <unistd.h>
+#ifndef NO_UNIX
+#  include <unistd.h>
+#endif
 #include <memory>
 
 #include "SocketBuffer.h"
diff --git a/src/Platform.cc b/src/Platform.cc
index 9f3ddb25..5ca24ab6 100644
--- a/src/Platform.cc
+++ b/src/Platform.cc
@@ -182,7 +182,7 @@ bool Platform::setUp()
   }
 #endif // HAVE_WINSOCK2_H
 
-#ifdef __MINGW32__
+#if defined(__MINGW32__) || defined(_MSC_VER)
   (void)_setmode(_fileno(stdin), _O_BINARY);
   (void)_setmode(_fileno(stdout), _O_BINARY);
   (void)_setmode(_fileno(stderr), _O_BINARY);
diff --git a/src/ProgressAwareEntry.h b/src/ProgressAwareEntry.h
index c804069f..cf18a38b 100644
--- a/src/ProgressAwareEntry.h
+++ b/src/ProgressAwareEntry.h
@@ -38,7 +38,9 @@
 #include "common.h"
 
 #include <stdint.h>
-#include <unistd.h>
+#ifndef NO_UNIX
+#  include <unistd.h>
+#endif
 
 namespace aria2 {
 
diff --git a/src/Range.h b/src/Range.h
index e7aef928..f360e783 100644
--- a/src/Range.h
+++ b/src/Range.h
@@ -37,7 +37,9 @@
 
 #include "common.h"
 
-#include <unistd.h>
+#ifndef NO_UNIX
+#  include <unistd.h>
+#endif
 
 namespace aria2 {
 
diff --git a/src/RequestGroup.cc b/src/RequestGroup.cc
index fd6801fc..1bd2341f 100644
--- a/src/RequestGroup.cc
+++ b/src/RequestGroup.cc
@@ -619,7 +619,7 @@ void RequestGroup::initPieceStorage()
       std::make_shared<SegmentMan>(downloadContext_, tempPieceStorage);
   pieceStorage_ = tempPieceStorage;
 
-#ifdef __MINGW32__
+#if defined(__MINGW32__) || defined(_MSC_VER)
   // Windows build: --file-allocation=falloc uses SetFileValidData
   // which requires SE_MANAGE_VOLUME_NAME privilege.  SetFileValidData
   // has security implications (see
diff --git a/src/RequestGroupMan.cc b/src/RequestGroupMan.cc
index 425351bb..ea57e7a2 100644
--- a/src/RequestGroupMan.cc
+++ b/src/RequestGroupMan.cc
@@ -34,7 +34,9 @@
 /* copyright --> */
 #include "RequestGroupMan.h"
 
-#include <unistd.h>
+#ifndef NO_UNIX
+#  include <unistd.h>
+#endif
 #include <cstring>
 #include <iomanip>
 #include <sstream>
diff --git a/src/SelectEventPoll.cc b/src/SelectEventPoll.cc
index d9397b20..7cadd955 100644
--- a/src/SelectEventPoll.cc
+++ b/src/SelectEventPoll.cc
@@ -34,7 +34,7 @@
 /* copyright --> */
 #include "SelectEventPoll.h"
 
-#ifdef __MINGW32__
+#if defined(__MINGW32__) || defined(_MSC_VER)
 #  include <cassert>
 #endif // __MINGW32__
 #include <cstring>
@@ -153,7 +153,7 @@ void SelectEventPoll::AsyncNameResolverEntry::process(fd_set* rfdsPtr,
 
 SelectEventPoll::SelectEventPoll()
 {
-#ifdef __MINGW32__
+#if defined(__MINGW32__) || defined(_MSC_VER)
   dummySocket_ = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
   assert(dummySocket_ != (sock_t)-1);
 #endif // __MINGW32__
@@ -162,7 +162,7 @@ SelectEventPoll::SelectEventPoll()
 
 SelectEventPoll::~SelectEventPoll()
 {
-#ifdef __MINGW32__
+#if defined(__MINGW32__) || defined(_MSC_VER)
   ::closesocket(dummySocket_);
 #endif // __MINGW32__
 }
@@ -175,7 +175,7 @@ void SelectEventPoll::poll(const struct timeval& tv)
   memcpy(&rfds, &rfdset_, sizeof(fd_set));
   memcpy(&wfds, &wfdset_, sizeof(fd_set));
 
-#ifdef __MINGW32__
+#if defined(__MINGW32__) || defined(_MSC_VER)
   fd_set efds;
   memcpy(&efds, &wfdset_, sizeof(fd_set));
 #endif // __MINGW32__
@@ -195,7 +195,7 @@ void SelectEventPoll::poll(const struct timeval& tv)
   int retval;
   do {
     struct timeval ttv = tv;
-#ifdef __MINGW32__
+#if defined(__MINGW32__) || defined(_MSC_VER)
     // winsock will report non-blocking connect() errors in efds,
     // unlike posix, which will mark such sockets as writable.
     retval = select(fdmax_ + 1, &rfds, &wfds, &efds, &ttv);
@@ -213,7 +213,7 @@ void SelectEventPoll::poll(const struct timeval& tv)
       if (FD_ISSET(e.getSocket(), &wfds)) {
         events |= EventPoll::EVENT_WRITE;
       }
-#ifdef __MINGW32__
+#if defined(__MINGW32__) || defined(_MSC_VER)
       if (FD_ISSET(e.getSocket(), &efds)) {
         events |= EventPoll::EVENT_ERROR;
       }
@@ -235,7 +235,7 @@ void SelectEventPoll::poll(const struct timeval& tv)
 #endif // ENABLE_ASYNC_DNS
 }
 
-#ifdef __MINGW32__
+#if defined(__MINGW32__) || defined(_MSC_VER)
 namespace {
 void checkFdCountMingw(const fd_set& fdset)
 {
@@ -251,7 +251,7 @@ void SelectEventPoll::updateFdSet()
 {
   FD_ZERO(&rfdset_);
   FD_ZERO(&wfdset_);
-#ifdef __MINGW32__
+#if defined(__MINGW32__) || defined(_MSC_VER)
   FD_SET(dummySocket_, &rfdset_);
   FD_SET(dummySocket_, &wfdset_);
   fdmax_ = dummySocket_;
@@ -262,7 +262,7 @@ void SelectEventPoll::updateFdSet()
   for (auto& i : socketEntries_) {
     auto& e = i.second;
     sock_t fd = e.getSocket();
-#ifndef __MINGW32__
+#if defined(__MINGW32__) || defined(_MSC_VER)
     if (fd < 0 || FD_SETSIZE <= fd) {
       A2_LOG_WARN("Detected file descriptor >= FD_SETSIZE or < 0. "
                   "Download may slow down or fail.");
@@ -271,13 +271,13 @@ void SelectEventPoll::updateFdSet()
 #endif // !__MINGW32__
     int events = e.getEvents();
     if (events & EventPoll::EVENT_READ) {
-#ifdef __MINGW32__
+#if defined(__MINGW32__) || defined(_MSC_VER)
       checkFdCountMingw(rfdset_);
 #endif // __MINGW32__
       FD_SET(fd, &rfdset_);
     }
     if (events & EventPoll::EVENT_WRITE) {
-#ifdef __MINGW32__
+#if defined(__MINGW32__) || defined(_MSC_VER)
       checkFdCountMingw(wfdset_);
 #endif // __MINGW32__
       FD_SET(fd, &wfdset_);
diff --git a/src/SelectEventPoll.h b/src/SelectEventPoll.h
index c09f423f..4764719e 100644
--- a/src/SelectEventPoll.h
+++ b/src/SelectEventPoll.h
@@ -151,7 +151,7 @@ private:
   fd_set rfdset_;
   fd_set wfdset_;
   sock_t fdmax_;
-#ifdef __MINGW32__
+#if defined(__MINGW32__) || defined(_MSC_VER)
   // Winsock select() doesn't work if no socket is in FD_SET. We add
   // this dummy socket to work around this problem
   sock_t dummySocket_;
diff --git a/src/SimpleRandomizer.cc b/src/SimpleRandomizer.cc
index 8dbef82f..4ebd1d46 100644
--- a/src/SimpleRandomizer.cc
+++ b/src/SimpleRandomizer.cc
@@ -35,7 +35,11 @@
 #include "SimpleRandomizer.h"
 
 #include <sys/types.h>
-#include <unistd.h>
+#ifndef NO_UNIX
+#  include <unistd.h>
+#endif
+#  include <unistd.h>
+#endif
 #include <cstdlib>
 #include <cassert>
 #include <cstring>
@@ -66,7 +70,7 @@ namespace {
 std::random_device rd;
 } // namespace
 
-#ifdef __MINGW32__
+#if defined(__MINGW32__) || defined(_MSC_VER)
 SimpleRandomizer::SimpleRandomizer()
 {
   BOOL r = ::CryptAcquireContext(&provider_, 0, 0, PROV_RSA_FULL,
@@ -79,7 +83,7 @@ SimpleRandomizer::SimpleRandomizer() : gen_(rd()) {}
 
 SimpleRandomizer::~SimpleRandomizer()
 {
-#ifdef __MINGW32__
+#if defined(__MINGW32__) || defined(_MSC_VER)
   CryptReleaseContext(provider_, 0);
 #endif
 }
@@ -92,7 +96,7 @@ long int SimpleRandomizer::getRandomNumber(long int to)
 
 void SimpleRandomizer::getRandomBytes(unsigned char* buf, size_t len)
 {
-#ifdef __MINGW32__
+#if defined(__MINGW32__) || defined(_MSC_VER)
   BOOL r = CryptGenRandom(provider_, len, reinterpret_cast<BYTE*>(buf));
   if (!r) {
     assert(r);
diff --git a/src/SimpleRandomizer.h b/src/SimpleRandomizer.h
index aea6fe05..d4882825 100644
--- a/src/SimpleRandomizer.h
+++ b/src/SimpleRandomizer.h
@@ -40,7 +40,7 @@
 #include <memory>
 #include <random>
 
-#ifdef __MINGW32__
+#if defined(__MINGW32__) || defined(_MSC_VER)
 #  include <wincrypt.h>
 #endif
 
@@ -52,7 +52,7 @@ private:
   SimpleRandomizer();
 
 private:
-#ifdef __MINGW32__
+#if defined(__MINGW32__) || defined(_MSC_VER)
   HCRYPTPROV provider_;
 #else
   std::mt19937 gen_;
diff --git a/src/SocketCore.cc b/src/SocketCore.cc
index e235f512..8b4d5234 100644
--- a/src/SocketCore.cc
+++ b/src/SocketCore.cc
@@ -38,7 +38,9 @@
 #  include <iphlpapi.h>
 #endif // HAVE_IPHLPAPI_H
 
-#include <unistd.h>
+#ifndef NO_UNIX
+#  include <unistd.h>
+#endif
 #ifdef HAVE_IFADDRS_H
 #  include <ifaddrs.h>
 #endif // HAVE_IFADDRS_H
@@ -68,13 +70,13 @@
 
 namespace aria2 {
 
-#ifndef __MINGW32__
+#if defined(__MINGW32__) || defined(_MSC_VER)
 #  define SOCKET_ERRNO (errno)
 #else
 #  define SOCKET_ERRNO (WSAGetLastError())
 #endif // __MINGW32__
 
-#ifdef __MINGW32__
+#if defined(__MINGW32__) || defined(_MSC_VER)
 #  define A2_EINPROGRESS WSAEWOULDBLOCK
 #  define A2_EWOULDBLOCK WSAEWOULDBLOCK
 #  define A2_EINTR WSAEINTR
@@ -93,7 +95,7 @@ namespace aria2 {
 #  endif // EWOULDBLOCK != EAGAIN
 #endif   // !__MINGW32__
 
-#ifdef __MINGW32__
+#if defined(__MINGW32__) || defined(_MSC_VER)
 #  define CLOSE(X) ::closesocket(X)
 #else
 #  define CLOSE(X) close(X)
@@ -102,7 +104,7 @@ namespace aria2 {
 namespace {
 std::string errorMsg(int errNum)
 {
-#ifndef __MINGW32__
+#if defined(__MINGW32__) || defined(_MSC_VER)
   return util::safeStrerror(errNum);
 #else
   auto msg = util::formatLastError(errNum);
@@ -595,7 +597,7 @@ void SocketCore::applyIpDscp()
 
 void SocketCore::setNonBlockingMode()
 {
-#ifdef __MINGW32__
+#if defined(__MINGW32__) || defined(_MSC_VER)
   static u_long flag = 1;
   if (::ioctlsocket(sockfd_, FIONBIO, &flag) == -1) {
     int errNum = SOCKET_ERRNO;
@@ -614,7 +616,7 @@ void SocketCore::setNonBlockingMode()
 
 void SocketCore::setBlockingMode()
 {
-#ifdef __MINGW32__
+#if defined(__MINGW32__) || defined(_MSC_VER)
   static u_long flag = 0;
   if (::ioctlsocket(sockfd_, FIONBIO, &flag) == -1) {
     int errNum = SOCKET_ERRNO;
@@ -654,7 +656,7 @@ void SocketCore::closeConnection()
   }
 }
 
-#ifndef __MINGW32__
+#if defined(__MINGW32__) || defined(_MSC_VER)
 #  define CHECK_FD(fd)                                                         \
     if (fd < 0 || FD_SETSIZE <= fd) {                                          \
       logger_->warn("Detected file descriptor >= FD_SETSIZE or < 0. "          \
@@ -681,7 +683,7 @@ bool SocketCore::isWritable(time_t timeout)
   }
   throw DL_RETRY_EX(fmt(EX_SOCKET_CHECK_WRITABLE, errorMsg(errNum).c_str()));
 #else // !HAVE_POLL
-#  ifndef __MINGW32__
+#  ifn defined(__MINGW32__) || defined(_MSC_VER)
   CHECK_FD(sockfd_);
 #  endif // !__MINGW32__
   fd_set fds;
@@ -726,7 +728,7 @@ bool SocketCore::isReadable(time_t timeout)
   }
   throw DL_RETRY_EX(fmt(EX_SOCKET_CHECK_READABLE, errorMsg(errNum).c_str()));
 #else // !HAVE_POLL
-#  ifndef __MINGW32__
+#  ifn defined(__MINGW32__) || defined(_MSC_VER)
   CHECK_FD(sockfd_);
 #  endif // !__MINGW32__
   fd_set fds;
@@ -759,7 +761,7 @@ ssize_t SocketCore::writeVector(a2iovec* iov, size_t iovcnt)
   wantRead_ = false;
   wantWrite_ = false;
   if (!secure_) {
-#ifdef __MINGW32__
+#if defined(__MINGW32__) || defined(_MSC_VER)
     DWORD nsent;
     int rv = WSASend(sockfd_, iov, iovcnt, &nsent, 0, 0, 0);
     if (rv == 0) {
@@ -1572,7 +1574,7 @@ bool ipv4AddrConfigured = true;
 bool ipv6AddrConfigured = true;
 } // namespace
 
-#ifdef __MINGW32__
+#if defined(__MINGW32__) || defined(_MSC_VER)
 namespace {
 const uint32_t APIPA_IPV4_BEGIN = 2851995649u; // 169.254.0.1
 const uint32_t APIPA_IPV4_END = 2852061183u;   // 169.254.255.255
diff --git a/src/a2io.h b/src/a2io.h
index 27ddc518..a8bbe7c4 100644
--- a/src/a2io.h
+++ b/src/a2io.h
@@ -37,7 +37,9 @@
 #include "common.h"
 #include <sys/types.h>
 #include <sys/stat.h>
-#include <unistd.h>
+#ifndef NO_UNIX
+#  include <unistd.h>
+#endif
 #include <fcntl.h>
 #include <cerrno>
 #ifdef HAVE_POLL_H
@@ -120,7 +122,7 @@
 #  define DEV_STDOUT "/dev/stdout"
 #endif // HAVE_WINSOCK2_H
 
-#ifdef __MINGW32__
+#if defined(__MINGW32__) || defined(_MSC_VER)
 #  define a2lseek(fd, offset, origin) _lseeki64(fd, offset, origin)
 #  define a2fseek(fd, offset, origin) _fseeki64(fd, offset, origin)
 #  define a2fstat(fd, buf) _fstati64(fd, buf)
@@ -190,7 +192,7 @@ extern int ftruncate64(int fd, off64_t length);
 #define OPEN_MODE S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH
 #define DIR_OPEN_MODE S_IRWXU | S_IRWXG | S_IRWXO
 
-#ifdef __MINGW32__
+#if defined(__MINGW32__) || defined(_MSC_VER)
 #  define A2_BAD_FD INVALID_HANDLE_VALUE
 #else // !__MINGW32__
 #  define A2_BAD_FD -1
diff --git a/src/a2netcompat.h b/src/a2netcompat.h
index c9b5b7e0..8f0683d2 100644
--- a/src/a2netcompat.h
+++ b/src/a2netcompat.h
@@ -37,13 +37,13 @@
 
 #include "a2io.h"
 
-#ifdef __MINGW32__
+#if defined(__MINGW32__) || defined(_MSC_VER)
 #  ifdef HAVE_WS2TCPIP_H
 #    include <ws2tcpip.h>
 #  endif // HAVE_WS2TCPIP_H
 #endif   // __MINGW32__
 
-#ifdef __MINGW32__
+#if defined(__MINGW32__) || defined(_MSC_VER)
 #  define a2_sockopt_t char*
 #  ifndef HAVE_GETADDRINFO
 #    define HAVE_GETADDRINFO
@@ -95,6 +95,7 @@
 
 #ifdef HAVE_WINSOCK2_H
 #  define sock_t SOCKET
+#  include <ws2def.h>
 #else
 #  define sock_t int
 #endif
@@ -105,7 +106,7 @@
 
 #define DEFAULT_AI_FLAGS AI_ADDRCONFIG
 
-#ifdef __MINGW32__
+#if defined(__MINGW32__) || defined(_MSC_VER)
 #  ifndef SHUT_WR
 #    define SHUT_WR SD_SEND
 #  endif // !SHUT_WR
@@ -141,7 +142,7 @@ struct Endpoint {
 #  define A2_IOV_MAX A2_DEFAULT_IOV_MAX
 #endif
 
-#ifdef __MINGW32__
+#if defined(__MINGW32__) || defined(_MSC_VER)
 typedef WSABUF a2iovec;
 #  define A2IOVEC_BASE buf
 #  define A2IOVEC_LEN len
diff --git a/src/a2time.h b/src/a2time.h
index 3b407608..c81e9c10 100644
--- a/src/a2time.h
+++ b/src/a2time.h
@@ -36,7 +36,10 @@
 #define D_A2TIME_H
 
 #include <time.h>
-#include <sys/time.h>
+
+#ifdef HAVE_SYS_TIME_H
+#  include <sys/time.h>
+#endif
 
 #include <chrono>
 
@@ -60,7 +63,7 @@
 #  include "asctime_r.h"
 #endif // HAVE_ASCTIME_R
 
-#ifdef __MINGW32__
+#if defined(__MINGW32__) || defined(_MSC_VER)
 #  define suseconds_t uint64_t
 #endif
 
diff --git a/src/asctime_r.c b/src/asctime_r.c
index 176c3c29..0d6eb25f 100644
--- a/src/asctime_r.c
+++ b/src/asctime_r.c
@@ -36,14 +36,14 @@
 #include <time.h>
 #include <stdlib.h>
 
-#ifdef __MINGW32__
+#if defined(__MINGW32__) || defined(_MSC_VER)
 #  define WIN32_LEAN_AND_MEAN
 #  include <windows.h>
 #endif // __MINGW32__
 
 #include "asctime_r.h"
 
-#ifdef __MINGW32__
+#if defined(__MINGW32__) || defined(_MSC_VER)
 
 static CRITICAL_SECTION asctime_r_cs;
 
diff --git a/src/common.h b/src/common.h
index d1a99719..de1a7a4d 100644
--- a/src/common.h
+++ b/src/common.h
@@ -39,7 +39,7 @@
 #  include "config.h"
 #endif
 
-#ifdef __MINGW32__
+#if defined(__MINGW32__) || defined(_MSC_VER)
 #  ifdef malloc
 #    undef malloc
 #  endif
@@ -48,7 +48,12 @@
 #  endif
 #endif // __MINGW32__
 
-#ifdef __MINGW32__
+#if defined(_MSC_VER)
+#include <BaseTsd.h>
+typedef SSIZE_T ssize_t;
+#endif
+
+#if defined(__MINGW32__) || defined(_MSC_VER)
 #  define WIN32_LEAN_AND_MEAN
 #  ifndef WINVER
 #    define WINVER 0x501
diff --git a/src/console.cc b/src/console.cc
index 6147bbb8..a0ebcf8f 100644
--- a/src/console.cc
+++ b/src/console.cc
@@ -34,7 +34,7 @@
 /* copyright --> */
 #include "console.h"
 #include "NullOutputFile.h"
-#ifdef __MINGW32__
+#if defined(__MINGW32__) || defined(_MSC_VER)
 #  include "WinConsoleFile.h"
 #else // !__MINGW32__
 #  include "BufferedFile.h"
@@ -56,7 +56,7 @@ void initConsole(bool suppress)
     consoleCout = consoleCerr = std::make_shared<NullOutputFile>();
   }
   else {
-#ifdef __MINGW32__
+#if defined(__MINGW32__) || defined(_MSC_VER)
     consoleCout = std::make_shared<WinConsoleFile>(STD_OUTPUT_HANDLE);
     consoleCerr = std::make_shared<WinConsoleFile>(STD_ERROR_HANDLE);
 #else  // !__MINGW32__
diff --git a/src/daemon.cc b/src/daemon.cc
index 60be5bb3..db4a1df6 100644
--- a/src/daemon.cc
+++ b/src/daemon.cc
@@ -34,7 +34,9 @@
 /* copyright --> */
 #include "daemon.h"
 
-#include <unistd.h>
+#ifndef NO_UNIX
+#  include <unistd.h>
+#endif
 #include <cstdio>
 #include <cstdlib>
 
diff --git a/src/fmt.h b/src/fmt.h
index ad2f065d..451d8f14 100644
--- a/src/fmt.h
+++ b/src/fmt.h
@@ -43,7 +43,7 @@
 namespace aria2 {
 
 std::string fmt(const char* fmt, ...)
-#ifdef __MINGW32__
+#if defined(__MINGW32__) || defined(_MSC_VER)
     __attribute__((format(__MINGW_PRINTF_FORMAT, 1, 2)))
 #else  // !__MINGW32__
     __attribute__((format(printf, 1, 2)))
diff --git a/src/gai_strerror.h b/src/gai_strerror.h
index da7b6ca7..effa6411 100644
--- a/src/gai_strerror.h
+++ b/src/gai_strerror.h
@@ -33,7 +33,7 @@
 extern "C" {
 #endif /* __cplusplus */
 
-#ifdef __MINGW32__
+#if defined(__MINGW32__) || defined(_MSC_VER)
 #  undef SIZE_MAX
 #endif // __MINGW32__
 
diff --git a/src/getaddrinfo.c b/src/getaddrinfo.c
index bfa3b4a3..59c29e04 100644
--- a/src/getaddrinfo.c
+++ b/src/getaddrinfo.c
@@ -79,7 +79,7 @@
 #  include "config.h"
 #endif
 
-#ifdef __MINGW32__
+#if defined(__MINGW32__) || defined(_MSC_VER)
 #  include <winsock2.h>
 #  undef ERROR
 #  include <ws2tcpip.h>
diff --git a/src/getaddrinfo.h b/src/getaddrinfo.h
index d841d4be..7faaedc4 100644
--- a/src/getaddrinfo.h
+++ b/src/getaddrinfo.h
@@ -33,7 +33,7 @@
 extern "C" {
 #endif /* __cplusplus */
 
-#ifdef __MINGW32__
+#if defined(__MINGW32__) || defined(_MSC_VER)
 #  undef SIZE_MAX
 #endif // __MINGW32__
 
@@ -41,7 +41,7 @@ extern "C" {
 #  include "config.h"
 #endif // HAVE_CONFIG_H
 
-#ifdef __MINGW32__
+#if defined(__MINGW32__) || defined(__MSVC__)
 #  ifndef _WIN32_WINNT
 #    define _WIN32_WINNT 0x501
 #  endif // _WIN32_WINNT
@@ -240,7 +240,7 @@ extern "C" {
 #endif
 
 /* Nexenta OS(GNU/Solaris OS) defines `struct addrinfo' in netdb.h */
-#if !defined(__MINGW32__) && !defined(__sun)
+#if !defined(__MINGW32__) && !defined(__sun) && !defined(_MSC_VER)
 
 /*
  * struct addrinfo.
@@ -256,7 +256,7 @@ struct addrinfo {
   struct addrinfo* ai_next;
 };
 
-#endif // !__MINGW32__ && !__sun
+#endif // !__MINGW32__ && !__sun && !defined(_MSC_VER)
 
 /*
  * Functions.
diff --git a/src/gettimeofday.c b/src/gettimeofday.c
index db292d94..8c7df499 100644
--- a/src/gettimeofday.c
+++ b/src/gettimeofday.c
@@ -25,7 +25,7 @@
 
 #include <sys/time.h>
 
-#ifdef __MINGW32__
+#if defined(__MINGW32__) || defined(_MSC_VER)
 
 #  define WIN32_LEAN_AND_MEAN
 #  include <windows.h>
diff --git a/src/gettimeofday.h b/src/gettimeofday.h
index c5231e9f..4424b729 100644
--- a/src/gettimeofday.h
+++ b/src/gettimeofday.h
@@ -36,7 +36,7 @@
 #ifndef _D_GETTIMEOFDAY_H
 #define _D_GETTIMEOFDAY_H 1
 
-#ifdef __MINGW32__
+#if defined(__MINGW32__) || defined(_MSC_VER)
 #  undef SIZE_MAX
 #endif // __MINGW32__
 
@@ -44,7 +44,9 @@
 #  include "config.h"
 #endif // HAVE_CONFIG_H
 
-#include <sys/time.h>
+#ifdef HAVE_SYS_TIME_H
+#  include <sys/time.h>
+#endif
 
 #ifdef __cplusplus
 extern "C" {
diff --git a/src/libgen.h b/src/libgen.h
index 79d55144..ee3a2b6d 100644
--- a/src/libgen.h
+++ b/src/libgen.h
@@ -40,7 +40,7 @@
 extern "C" {
 #endif /* __cplusplus */
 
-#ifdef __MINGW32__
+#if defined(__MINGW32__) || defined(_MSC_VER)
 
 char* basename(char* path);
 char* dirname(char* path);
diff --git a/src/localtime_r.c b/src/localtime_r.c
index 47294558..9a012dad 100644
--- a/src/localtime_r.c
+++ b/src/localtime_r.c
@@ -36,14 +36,14 @@
 #include <time.h>
 #include <stdlib.h>
 
-#ifdef __MINGW32__
+#if defined(__MINGW32__) || defined(_MSC_VER)
 #  define WIN32_LEAN_AND_MEAN
 #  include <windows.h>
 #endif // __MINGW32__
 
 #include "localtime_r.h"
 
-#ifdef __MINGW32__
+#if defined(__MINGW32__) || defined(_MSC_VER)
 
 static CRITICAL_SECTION localtime_r_cs;
 
diff --git a/src/main.cc b/src/main.cc
index f14cea6a..cd82ebc5 100644
--- a/src/main.cc
+++ b/src/main.cc
@@ -34,9 +34,11 @@
 /* copyright --> */
 #include "common.h"
 
-#include <unistd.h>
+#ifndef NO_UNIX
+#  include <unistd.h>
+#endif
 
-#ifdef __MINGW32__
+#if defined(__MINGW32__) || defined(_MSC_VER)
 #  include <shellapi.h>
 #endif // __MINGW32__
 
@@ -53,7 +55,7 @@ namespace aria2 {
 
 error_code::Value main(int argc, char** argv)
 {
-#ifdef __MINGW32__
+#if defined(__MINGW32__) || defined(_MSC_VER)
   int winArgc;
   auto winArgv = CommandLineToArgvW(GetCommandLineW(), &winArgc);
   if (winArgv == nullptr) {
diff --git a/src/util.cc b/src/util.cc
index 07502c0e..1e172323 100644
--- a/src/util.cc
+++ b/src/util.cc
@@ -96,7 +96,7 @@
 
 namespace aria2 {
 
-#ifdef __MINGW32__
+#if defined(__MINGW32__) || defined(_MSC_VER)
 namespace {
 int utf8ToWChar(wchar_t* out, size_t outLength, const char* src)
 {
@@ -1742,7 +1742,7 @@ void setGlobalSignalHandler(int sig, sigset_t* mask, signal_handler_t handler,
 #endif // HAVE_SIGACTION
 }
 
-#ifndef __MINGW32__
+#if defined(__MINGW32__) || defined(_MSC_VER)
 std::string getHomeDir()
 {
   const char* p = getenv("HOME");
@@ -1789,7 +1789,7 @@ std::string getXDGDir(const std::string& environmentVariable,
   std::string filename;
   const char* p = getenv(environmentVariable.c_str());
   if (p &&
-#ifndef __MINGW32__
+#if defined(__MINGW32__) || defined(_MSC_VER)
       p[0] == '/'
 #else  // __MINGW32__
       p[0] && p[1] == ':'
@@ -2112,7 +2112,7 @@ std::string applyDir(const std::string& dir, const std::string& relPath)
       s += relPath;
     }
   }
-#ifdef __MINGW32__
+#if defined(__MINGW32__) || defined(_MSC_VER)
   for (std::string::iterator i = s.begin(), eoi = s.end(); i != eoi; ++i) {
     if (*i == '\\') {
       *i = '/';
@@ -2179,7 +2179,7 @@ bool detectDirTraversal(const std::string& s)
 std::string escapePath(const std::string& s)
 {
 // We don't escape '/' because we use it as a path separator.
-#ifdef __MINGW32__
+#if defined(__MINGW32__) || defined(_MSC_VER)
   static const char WIN_INVALID_PATH_CHARS[] = {'"', '*', ':',  '<',
                                                 '>', '?', '\\', '|'};
 #endif // __MINGW32__
@@ -2187,7 +2187,7 @@ std::string escapePath(const std::string& s)
   for (auto cc : s) {
     unsigned char c = cc;
     if (in(c, 0x00u, 0x1fu) || c == 0x7fu
-#ifdef __MINGW32__
+#if defined(__MINGW32__) || defined(_MSC_VER)
         || std::find(std::begin(WIN_INVALID_PATH_CHARS),
                      std::end(WIN_INVALID_PATH_CHARS),
                      c) != std::end(WIN_INVALID_PATH_CHARS)
@@ -2234,7 +2234,7 @@ void executeHook(const std::string& command, a2_gid_t gid, size_t numFiles,
 {
   const std::string gidStr = GroupId::toHex(gid);
   const std::string numFilesStr = util::uitos(numFiles);
-#ifndef __MINGW32__
+#if defined(__MINGW32__) || defined(_MSC_VER)
   A2_LOG_INFO(fmt("Executing user command: %s %s %s %s", command.c_str(),
                   gidStr.c_str(), numFilesStr.c_str(), firstFilename.c_str()));
   pid_t cpid = fork();
@@ -2483,7 +2483,7 @@ TLSVersion toTLSVersion(const std::string& ver)
 }
 #endif // ENABLE_SSL
 
-#ifdef __MINGW32__
+#if defined(__MINGW32__) || defined(_MSC_VER)
 std::string formatLastError(int errNum)
 {
   std::array<char, 4_k> buf;
@@ -2502,7 +2502,7 @@ std::string formatLastError(int errNum)
 
 void make_fd_cloexec(int fd)
 {
-#ifndef __MINGW32__
+#if defined(__MINGW32__) || defined(_MSC_VER)
   int flags;
 
   // TODO from linux man page, fcntl() with F_GETFD or F_SETFD does
@@ -2519,7 +2519,7 @@ void make_fd_cloexec(int fd)
 #endif // !__MINGW32__
 }
 
-#ifdef __MINGW32__
+#if defined(__MINGW32__) || defined(_MSC_VER)
 bool gainPrivilege(LPCTSTR privName)
 {
   LUID luid;
diff --git a/src/util.h b/src/util.h
index bb7d8d3e..cdb6a950 100644
--- a/src/util.h
+++ b/src/util.h
@@ -37,7 +37,9 @@
 
 #include "common.h"
 
-#include <sys/time.h>
+#ifdef HAVE_SYS_TIME_H
+#  include <sys/time.h>
+#endif
 #include <limits.h>
 #include <stdint.h>
 
@@ -95,7 +97,7 @@ inline uint64_t ntoh64(uint64_t x) { return byteswap64(x); }
 inline uint64_t hton64(uint64_t x) { return byteswap64(x); }
 #endif // !WORDS_BIGENDIAN
 
-#ifdef __MINGW32__
+#if defined(__MINGW32__) || defined(_MSC_VER)
 std::wstring utf8ToWChar(const std::string& src);
 
 std::wstring utf8ToWChar(const char* str);
@@ -109,6 +111,12 @@ std::string toForwardSlash(const std::string& src);
 #  define utf8ToNative(src) src
 #endif // !__MINGW32__
 
+#if defined(_MSC_VER)
+#include <BaseTsd.h>
+typedef SSIZE_T ssize_t;
+#endif
+
+
 namespace util {
 
 extern const char DEFAULT_STRIP_CHARSET[];
@@ -863,7 +871,7 @@ bool tlsHostnameMatch(const std::string& pattern, const std::string& hostname);
 TLSVersion toTLSVersion(const std::string& ver);
 #endif // ENABLE_SSL
 
-#ifdef __MINGW32__
+#if defined(__MINGW32__) || defined(_MSC_VER)
 // Formats error message for error code errNum, which is the return
 // value of GetLastError().  On error, this function returns empty
 // string.
@@ -875,7 +883,7 @@ std::string formatLastError(int errNum);
 // CreateProcess call.
 void make_fd_cloexec(int fd);
 
-#ifdef __MINGW32__
+#if defined(__MINGW32__) || defined(_MSC_VER)
 bool gainPrivilege(LPCTSTR privName);
 #endif // __MINGW32__
 
diff --git a/test/FileTest.cc b/test/FileTest.cc
index ca78217e..e4c2f01a 100644
--- a/test/FileTest.cc
+++ b/test/FileTest.cc
@@ -97,7 +97,7 @@ void FileTest::testRemove()
   CPPUNIT_ASSERT(!f.remove());
 
   std::string dir = A2_TEST_OUT_DIR "/aria2_FileTest_testRemove_testdir";
-#ifdef __MINGW32__
+#if defined(__MINGW32__) || defined(_MSC_VER)
   mkdir(dir.c_str());
 #else
   mkdir(dir.c_str(), 0777);
@@ -183,7 +183,7 @@ void FileTest::testGetDirname()
     File f("");
     CPPUNIT_ASSERT_EQUAL(std::string(""), f.getDirname());
   }
-#ifdef __MINGW32__
+#if defined(__MINGW32__) || defined(_MSC_VER)
   {
     File f("c:\\foo\\bar");
     CPPUNIT_ASSERT_EQUAL(std::string("c:\\foo"), f.getDirname());
@@ -221,7 +221,7 @@ void FileTest::testGetBasename()
     File f("");
     CPPUNIT_ASSERT_EQUAL(std::string(""), f.getBasename());
   }
-#ifdef __MINGW32__
+#if defined(__MINGW32__) || defined(_MSC_VER)
   {
     File f("c:\\foo\\bar");
     CPPUNIT_ASSERT_EQUAL(std::string("bar"), f.getBasename());
diff --git a/test/LpdMessageDispatcherTest.cc b/test/LpdMessageDispatcherTest.cc
index e819d5f8..28467dfb 100644
--- a/test/LpdMessageDispatcherTest.cc
+++ b/test/LpdMessageDispatcherTest.cc
@@ -44,7 +44,7 @@ void LpdMessageDispatcherTest::testCreateLpdRequest()
 void LpdMessageDispatcherTest::testSendMessage()
 {
   std::shared_ptr<SocketCore> recvsock(new SocketCore(SOCK_DGRAM));
-#ifdef __MINGW32__
+#if defined(__MINGW32__) || defined(_MSC_VER)
   recvsock->bindWithFamily(LPD_MULTICAST_PORT, AF_INET);
 #else  // !__MINGW32__
   recvsock->bind(LPD_MULTICAST_ADDR, LPD_MULTICAST_PORT, AF_INET);
diff --git a/test/Metalink2RequestGroupTest.cc b/test/Metalink2RequestGroupTest.cc
index 47e1e213..4dd34075 100644
--- a/test/Metalink2RequestGroupTest.cc
+++ b/test/Metalink2RequestGroupTest.cc
@@ -208,7 +208,7 @@ void Metalink2RequestGroupTest::testGenerate_groupByMetaurl()
 
 void Metalink2RequestGroupTest::testGenerate_dosDirTraversal()
 {
-#ifdef __MINGW32__
+#if defined(__MINGW32__) || defined(_MSC_VER)
 #  ifdef ENABLE_BITTORRENT
   std::vector<std::shared_ptr<RequestGroup>> groups;
   option_->put(PREF_DIR, "/tmp");
diff --git a/test/TimeTest.cc b/test/TimeTest.cc
index c1e2f564..0132175e 100644
--- a/test/TimeTest.cc
+++ b/test/TimeTest.cc
@@ -96,7 +96,7 @@ void TimeTest::testToHTTPDate()
 {
 // This test disabled for MinGW32, because the garbage will be
 // displayed and it hides real errors.
-#ifndef __MINGW32__
+#if defined(__MINGW32__) || defined(_MSC_VER)
   Time t(1220714793);
   CPPUNIT_ASSERT_EQUAL(std::string("Sat, 06 Sep 2008 15:26:33 GMT"),
                        t.toHTTPDate());
diff --git a/test/UtilTest2.cc b/test/UtilTest2.cc
index b919b71c..d6635e0a 100644
--- a/test/UtilTest2.cc
+++ b/test/UtilTest2.cc
@@ -789,7 +789,7 @@ void UtilTest2::testApplyDir()
 void UtilTest2::testFixTaintedBasename()
 {
   CPPUNIT_ASSERT_EQUAL(std::string("a%2Fb"), util::fixTaintedBasename("a/b"));
-#ifdef __MINGW32__
+#if defined(__MINGW32__) || defined(_MSC_VER)
   CPPUNIT_ASSERT_EQUAL(std::string("a%5Cb"), util::fixTaintedBasename("a\\b"));
 #else  // !__MINGW32__
   CPPUNIT_ASSERT_EQUAL(std::string("a\\b"), util::fixTaintedBasename("a\\b"));
@@ -827,7 +827,7 @@ void UtilTest2::testEscapePath()
                        util::escapePath(std::string("foo") + (char)0x00 +
                                         std::string("bar") + (char)0x00 +
                                         (char)0x01));
-#ifdef __MINGW32__
+#if defined(__MINGW32__) || defined(_MSC_VER)
   CPPUNIT_ASSERT_EQUAL(std::string("foo%5Cbar"), util::escapePath("foo\\bar"));
 #else  // !__MINGW32__
   CPPUNIT_ASSERT_EQUAL(std::string("foo\\bar"), util::escapePath("foo\\bar"));