diff --git a/vm/Config.windows b/vm/Config.windows
index b0b1352cb2..11df403541 100644
--- a/vm/Config.windows
+++ b/vm/Config.windows
@@ -1,4 +1,4 @@
-CFLAGS += -DWINDOWS -mno-cygwin
+CFLAGS += -mno-cygwin
 LIBS = -lm
 PLAF_DLL_OBJS += vm/os-windows.o
 SHARED_FLAG = -shared
diff --git a/vm/Config.x86.64 b/vm/Config.x86.64
index 314c14fe05..8b13789179 100644
--- a/vm/Config.x86.64
+++ b/vm/Config.x86.64
@@ -1 +1 @@
-CFLAGS += -DFACTOR_64
+
diff --git a/vm/os-windows.hpp b/vm/os-windows.hpp
index a7c69571d9..6a280ea580 100644
--- a/vm/os-windows.hpp
+++ b/vm/os-windows.hpp
@@ -18,7 +18,6 @@ typedef wchar_t vm_char;
 #define STRCMP wcscmp
 #define STRNCMP wcsncmp
 #define STRDUP _wcsdup
-#define MIN(a,b) ((a)>(b)?(b):(a))
 #define FTELL ftello64
 #define FSEEK fseeko64
 
diff --git a/vm/platform.hpp b/vm/platform.hpp
index 7b4356af56..a3434e2ad0 100644
--- a/vm/platform.hpp
+++ b/vm/platform.hpp
@@ -2,6 +2,7 @@
 	#define FACTOR_ARM
 #elif defined(__amd64__) || defined(__x86_64__)
 	#define FACTOR_AMD64
+	#define FACTOR_64
 #elif defined(i386) || defined(__i386) || defined(__i386__) || defined(WIN32)
 	#define FACTOR_X86
 #elif defined(__POWERPC__) || defined(__ppc__) || defined(_ARCH_PPC)
@@ -10,6 +11,10 @@
 	#error "Unsupported architecture"
 #endif
 
+#ifdef WIN32
+	#define WINDOWS
+#endif
+
 #if defined(WINDOWS)
 	#if defined(WINCE)
 		#include "os-windows-ce.hpp"
@@ -18,6 +23,7 @@
 	#endif
 
 	#include "os-windows.hpp"
+
 	#if defined(FACTOR_AMD64)
 		#include "os-windows-nt.64.hpp"
 	#elif defined(FACTOR_X86)