diff --git a/Source/Glide64/Debugger.cpp b/Source/Glide64/Debugger.cpp
index 9364139e2..10f22718c 100644
--- a/Source/Glide64/Debugger.cpp
+++ b/Source/Glide64/Debugger.cpp
@@ -70,7 +70,7 @@ int  grid = 0;
 static const char *tri_type[4] = { "TRIANGLE", "TEXRECT", "FILLRECT", "BACKGROUND" };
 
 //Platform-specific stuff
-#ifndef WIN32
+#ifndef _WIN32
 typedef struct dbgPOINT {
    int x;
    int y;
diff --git a/Source/Glide64/Gfx_1.3.h b/Source/Glide64/Gfx_1.3.h
index b14e786c6..0b9358750 100644
--- a/Source/Glide64/Gfx_1.3.h
+++ b/Source/Glide64/Gfx_1.3.h
@@ -106,7 +106,7 @@ typedef unsigned char boolean;
 #define GLIDE64_CATCH catch (...)
 #endif
 
-#ifndef WIN32
+#ifndef _WIN32
 typedef void* HWND;
 #endif
 
diff --git a/Source/GlideHQ/Ext_TxFilter.h b/Source/GlideHQ/Ext_TxFilter.h
index 9a7010c3d..f8833a572 100644
--- a/Source/GlideHQ/Ext_TxFilter.h
+++ b/Source/GlideHQ/Ext_TxFilter.h
@@ -24,7 +24,7 @@
 #ifndef __EXT_TXFILTER_H__
 #define __EXT_TXFILTER_H__
 
-#ifdef WIN32
+#ifdef _WIN32
 #include <windows.h>
 #define TXHMODULE HMODULE
 #define DLOPEN(a) LoadLibraryW(a)
diff --git a/Source/GlideHQ/TxFilter.cpp b/Source/GlideHQ/TxFilter.cpp
index 9d98f65a3..68a3dbdd0 100644
--- a/Source/GlideHQ/TxFilter.cpp
+++ b/Source/GlideHQ/TxFilter.cpp
@@ -625,7 +625,7 @@ TxFilter::dmptx(uint8 *src, int width, int height, int rowStridePixel, uint16 gf
     } else {
       tmpbuf.SetNameExtension(stdstr_f("%ls#%08X#%01X#%01X_all.png",_ident.c_str(),(uint32)(r_crc64 & 0xffffffff),(n64fmt >> 8),(n64fmt & 0xf)).c_str());
     }
-#ifdef WIN32
+#ifdef _WIN32
     if ((fp = fopen(tmpbuf, "wb")) != NULL) {
 #else
     char cbuf[MAX_PATH];
diff --git a/Source/GlideHQ/TxHiResCache.cpp b/Source/GlideHQ/TxHiResCache.cpp
index b78533ac4..e4ada0893 100644
--- a/Source/GlideHQ/TxHiResCache.cpp
+++ b/Source/GlideHQ/TxHiResCache.cpp
@@ -24,7 +24,7 @@
 /* 2007 Gonetz <gonetz(at)ngs.ru>
  * Added callback to display hires texture info. */
 
-#ifdef WIN32
+#ifdef _WIN32
 #pragma warning(disable: 4786)
 #endif
 
@@ -225,12 +225,12 @@ boolean TxHiResCache::loadHiResTextures(LPCSTR dir_path, boolean replace)
 			/* XXX case sensitivity fiasco!
 			* files must use _a, _rgb, _all, _allciByRGBA, _ciByRGBA, _ci
 			* and file extensions must be in lower case letters! */
-			#ifdef WIN32
+#ifdef _WIN32
 			{
 				unsigned int i;
 				for (i = 0; i < strlen(fname); i++) fname[i] = (char)tolower(fname[i]);
 			}
-			#endif
+#endif
 			ident.assign(fname);
 
 			/* read in Rice's file naming convention */
@@ -240,12 +240,12 @@ boolean TxHiResCache::loadHiResTextures(LPCSTR dir_path, boolean replace)
 			/* XXX case sensitivity fiasco!
 			* files must use _a, _rgb, _all, _allciByRGBA, _ciByRGBA, _ci
 			* and file extensions must be in lower case letters! */
-			#ifdef WIN32
+#ifdef _WIN32
 			{
 				unsigned int i;
 				for (i = 0; i < strlen(fname); i++) fname[i] = (char)tolower(fname[i]);
 			}
-			#endif
+#endif
 			pfname = fname + strlen(fname) - 4;
 			if (!(pfname == strstr(fname, ".png") ||
 				  pfname == strstr(fname, ".bmp") ||
@@ -451,7 +451,7 @@ boolean TxHiResCache::loadHiResTextures(LPCSTR dir_path, boolean replace)
      */
     if (pfname == strstr(fname, "_all.png") ||
         pfname == strstr(fname, "_all.dds") ||
-#ifdef WIN32
+#ifdef _WIN32
         pfname == strstr(fname, "_allcibyrgba.png") ||
         pfname == strstr(fname, "_allcibyrgba.dds") ||
         pfname == strstr(fname, "_cibyrgba.png") ||