diff --git a/reactos/tools/sysreg/namedpipe_reader.cpp b/reactos/tools/sysreg/namedpipe_reader.cpp
index 24385ef7f2c..5175422617d 100644
--- a/reactos/tools/sysreg/namedpipe_reader.cpp
+++ b/reactos/tools/sysreg/namedpipe_reader.cpp
@@ -14,7 +14,7 @@ namespace System_
 {
 #define MIN(a, b)  (((a) < (b)) ? (a) : (b))
 
-#ifdef __linux__
+#ifndef WIN32
     const char * NamedPipeReader::s_LineBreak = "\x0A\0";
 #else
     const char * NamedPipeReader::s_LineBreak = "\x0D\x0A\0";
@@ -46,7 +46,7 @@ namespace System_
             cerr << "NamedPipeReader::openPipe> pipe already open" << endl;
             return false;
         }
-#ifndef __linux__
+#ifdef WIN32
         h_Pipe = CreateFile(PipeCmd.c_str(),
                             GENERIC_WRITE | GENERIC_READ,
                             0,
@@ -105,7 +105,7 @@ namespace System_
             cerr << "NamedPipeReader::closePipe> pipe is not open" << endl;
             return false;
         }
-#ifdef __linux__
+#ifndef WIN32
         close(h_Pipe);
 #else
         DisconnectNamedPipe(h_Pipe);
@@ -274,7 +274,7 @@ namespace System_
     bool NamedPipeReader::readPipe(char * buffer, int bufferlength, long & bytesread)
     {
         
-#ifdef __linux__
+#ifndef WIN32
         long cbRead = read(h_Pipe,
                            buffer,
                            (bufferlength-1) * sizeof(char));
diff --git a/reactos/tools/sysreg/os_support.cpp b/reactos/tools/sysreg/os_support.cpp
index 9953df7e3b4..f8b610bbbba 100644
--- a/reactos/tools/sysreg/os_support.cpp
+++ b/reactos/tools/sysreg/os_support.cpp
@@ -38,7 +38,7 @@ namespace System_
             }
         }
 
-#ifdef __linux__
+#ifndef WIN32
         if (s_Entries.size())
         {
             long secs = s_Entries[i]->tm.tv_sec - tm.tv_sec;
@@ -54,7 +54,7 @@ namespace System_
     void OsSupport::cancelAlarms()
     {
 
-#ifndef __linux__
+#ifdef WIN32
         if (s_hThread)
         {
             TerminateThread(s_hThread, 0);
@@ -73,7 +73,7 @@ namespace System_
     }
 
 
-#ifndef __linux__
+#ifdef WIN32
 
     HANDLE OsSupport::s_hThread = 0;
     static HANDLE hTimer;
diff --git a/reactos/tools/sysreg/os_support.h b/reactos/tools/sysreg/os_support.h
index 805256bd4fd..2d33a70e6da 100644
--- a/reactos/tools/sysreg/os_support.h
+++ b/reactos/tools/sysreg/os_support.h
@@ -10,7 +10,7 @@
  * PROGRAMMERS: Johannes Anderwald (johannes.anderwald at sbox tugraz at)
  */
 
-#ifndef __linux__
+#ifdef WIN32
 #include <windows.h>
 #else
 #include <unistd.h>
@@ -140,7 +140,7 @@ namespace System_
 		OsSupport()
 		{}
 
-#ifdef __linux__
+#ifndef WIN32
         static struct sigaction s_sact;
 #else
         static HANDLE s_hThread;
diff --git a/reactos/tools/sysreg/rosboot_test.cpp b/reactos/tools/sysreg/rosboot_test.cpp
index 45a91837451..da4ad9d6a1f 100644
--- a/reactos/tools/sysreg/rosboot_test.cpp
+++ b/reactos/tools/sysreg/rosboot_test.cpp
@@ -46,7 +46,7 @@ namespace Sysreg_
 	string RosBootTest::XEN_CONFIG_FILE = "XEN_CONFIG_FILE";
 	string RosBootTest::XEN_CONFIG_NAME = "XEN_CONFIG_NAME";
 
-#ifdef __linux__
+#ifndef WIN32
     string RosBootTest::ROS_EMU_PATH = "ROS_EMU_PATH_LIN";
 #else
     string RosBootTest::ROS_EMU_PATH = "ROS_EMU_PATH_WIN";
@@ -117,7 +117,7 @@ namespace Sysreg_
         img = "output-i386";
 
         EnvironmentVariable::getValue("ROS_OUTPUT", img);
-#ifdef __linux__
+#ifndef WIN32
         img += "/ros.hd";
 #else
         img += "\\ros.hd";
@@ -159,7 +159,7 @@ namespace Sysreg_
         }
 
 
-#ifdef __linux__
+#ifndef WIN32
         qemuimgdir += "/qemu-img";
 
 #else
@@ -176,7 +176,7 @@ namespace Sysreg_
        const char * options[] = {NULL,
                                   "create",
                                   "-f",
-#ifdef __linux__
+#ifndef WIN32
                                   "raw",
 #else
                                   "vmdk",
@@ -241,7 +241,7 @@ namespace Sysreg_
     {
         string::size_type pos;
 
-#ifdef __linux__
+#ifndef WIN32
         pos = m_EmuPath.find_last_of("/");
 #else
         pos = m_EmuPath.find_last_of("\\");
@@ -266,7 +266,7 @@ namespace Sysreg_
             m_MaxMem = "64";
         }
 
-#ifdef __linux__
+#ifndef WIN32
 
         if (mktemp(pipename))
         {
@@ -332,7 +332,7 @@ namespace Sysreg_
             return false;
         }
 
-#ifdef __linux__
+#ifndef WIN32
                 /* on linux we need get pid in order to be able
                  * to terminate the emulator in case of errors
                  * on windows we can get pid as return of CreateProcess
@@ -369,7 +369,7 @@ namespace Sysreg_
         {
            pipe = pipe.substr(0, pos);
         }
-#ifdef __linux__
+#ifndef WIN32
         m_Src = pipe;
 #else
 	m_Src = "\\\\.\\pipe\\" + pipe.substr(0, pos);
@@ -577,7 +577,7 @@ namespace Sysreg_
                 return false;
             }
         }
-#ifdef __linux__
+#ifndef WIN32
     if (mkfifo(m_Src.c_str(), 400))
     {
 /*
@@ -802,7 +802,7 @@ namespace Sysreg_
             cleanup(conf_parser);
             return false;
         }
-#ifdef __linux__
+#ifndef WIN32
         /*
          * For linux systems we can only
          * check if the emulator runs by
@@ -832,7 +832,7 @@ namespace Sysreg_
         }
 #endif
         OsSupport::cancelAlarms();
-#ifdef __linux__
+#ifndef WIN32
      //   OsSupport::setAlarm (m_MaxTime, m_Pid);
      //   OsSupport::setAlarm(m_MaxTime, getpid());
 #else
diff --git a/reactos/tools/sysreg/rosboot_test.h b/reactos/tools/sysreg/rosboot_test.h
index 2457f1a0659..bc2345fd76e 100644
--- a/reactos/tools/sysreg/rosboot_test.h
+++ b/reactos/tools/sysreg/rosboot_test.h
@@ -30,12 +30,12 @@
 #include <cstdlib>
 #include <cstring>
 #include <ctime>
-#ifndef __linux__
+#ifdef WIN32
 #include <io.h>
 #include <errno.h>
 #endif
 
-#ifdef __linux__
+#ifndef WIN32
 #include <unistd.h>
 #include <sys/types.h>
 #if defined(__FreeBSD__) || defined(__APPLE__)
diff --git a/reactos/tools/sysreg/user_types.h b/reactos/tools/sysreg/user_types.h
index a13543cdc32..a1ed1870599 100644
--- a/reactos/tools/sysreg/user_types.h
+++ b/reactos/tools/sysreg/user_types.h
@@ -13,7 +13,7 @@
 #include <string>
 #include <iostream>
 
-#ifndef __linux__
+#ifdef WIN32
 #define popen _popen
 #define pclose _pclose
 #endif