diff --git a/src/source/DataModelV2/Instance.cpp b/src/source/DataModelV2/Instance.cpp
index ab5dbdc..eed73be 100644
--- a/src/source/DataModelV2/Instance.cpp
+++ b/src/source/DataModelV2/Instance.cpp
@@ -1,4 +1,3 @@
-#define WINVER	0x0400
 #include <G3DAll.h>
 #include "DataModelV2/Instance.h"
 
diff --git a/src/source/propertyGrid.cpp b/src/source/propertyGrid.cpp
index 13f16b2..591214b 100644
--- a/src/source/propertyGrid.cpp
+++ b/src/source/propertyGrid.cpp
@@ -36,7 +36,7 @@
 #endif
 
 #ifndef _WIN32_WINNT // Necessary for WM_MOUSEWHEEL support
-#define _WIN32_WINNT 0x0500
+#define _WIN32_WINNT 0x0400
 #endif
 
 // MSVC++ Support