diff --git a/src/duality/duality.h b/src/duality/duality.h
index e1d058f10..7db9a4479 100755
--- a/src/duality/duality.h
+++ b/src/duality/duality.h
@@ -25,7 +25,7 @@ Revision History:
 #include <map>
 
 // make hash_map and hash_set available
-#ifndef WIN32
+#ifndef _WINDOWS
 using namespace stl_ext;
 #endif
 
@@ -782,7 +782,7 @@ protected:
       };
 
       
-#ifdef WIN32
+#ifdef _WINDOWS
        __declspec(dllexport)
 #endif
        void FromClauses(const std::vector<Term> &clauses);
diff --git a/src/duality/duality_wrapper.h b/src/duality/duality_wrapper.h
index 2b0045023..8a77a69da 100755
--- a/src/duality/duality_wrapper.h
+++ b/src/duality/duality_wrapper.h
@@ -1402,7 +1402,7 @@ namespace hash_space {
 }
 
 // to make Duality::ast hashable in windows
-#ifdef WIN32 
+#ifdef _WINDOWS 
 template <> inline
 size_t stdext::hash_value<Duality::ast >(const Duality::ast& s)
 {	
@@ -1446,7 +1446,7 @@ namespace hash_space {
 }
 
 // to make Duality::func_decl hashable in windows
-#ifdef WIN32 
+#ifdef _WINDOWS 
 template <> inline
 size_t stdext::hash_value<Duality::func_decl >(const Duality::func_decl& s)
 {	
diff --git a/src/interp/iz3hash.h b/src/interp/iz3hash.h
index 94f282265..a564026bd 100755
--- a/src/interp/iz3hash.h
+++ b/src/interp/iz3hash.h
@@ -42,7 +42,7 @@ Revision History:
 #include <ext/hash_map>
 #include <ext/hash_set>
 #else
-#ifdef WIN32
+#ifdef _WINDOWS
 #define stl_ext stdext
 #define hash_space std
 #include <hash_map>
@@ -61,7 +61,7 @@ Revision History:
 
 // stupid STL doesn't include hash function for class string
 
-#ifndef WIN32 
+#ifndef _WINDOWS 
 
 namespace stl_ext {
   template <>
@@ -86,7 +86,7 @@ namespace hash_space {
   };
 }
 
-#ifdef WIN32 
+#ifdef _WINDOWS 
 template <> inline
 size_t stdext::hash_value<std::pair<int,int> >(const std::pair<int,int>& p)
 {	// hash _Keyval to size_t value one-to-one
@@ -112,7 +112,7 @@ size_t stdext::hash_value<std::pair<T *, T *> >(const std::pair<T *, T *>& p)
 }
 #endif
 
-#ifdef WIN32
+#ifdef _WINDOWS
 
 namespace std {
     template <>
@@ -139,7 +139,7 @@ namespace std {
 #endif
 
 
-#ifndef WIN32
+#ifndef _WINDOWS
 
 #if 0
 namespace stl_ext {
@@ -155,7 +155,7 @@ namespace stl_ext {
 
 #endif
 
-#ifdef WIN32
+#ifdef _WINDOWS
 
 
 
diff --git a/src/interp/iz3mgr.h b/src/interp/iz3mgr.h
index e974a199b..d9593ced5 100755
--- a/src/interp/iz3mgr.h
+++ b/src/interp/iz3mgr.h
@@ -127,7 +127,7 @@ namespace hash_space {
 }
 
 // to make ast_r hashable in windows
-#ifdef WIN32 
+#ifdef _WINDOWS 
 template <> inline
 size_t stdext::hash_value<ast_r >(const ast_r& s)
 {