diff --git a/SConstruct b/SConstruct
index fc4d792cca9..3ae4c04dec6 100644
--- a/SConstruct
+++ b/SConstruct
@@ -576,7 +576,7 @@ elif "win32" == os.sys.platform:
     # some warnings we don't like:
     env.Append( CPPFLAGS=" /wd4355 /wd4800 /wd4267 /wd4244 " )
     
-    env.Append( CPPDEFINES=["WIN32","_CONSOLE","_CRT_SECURE_NO_WARNINGS","HAVE_CONFIG_H","PCRE_STATIC","SUPPORT_UCP","SUPPORT_UTF8","PSAPI_VERSION=1" ] )
+    env.Append( CPPDEFINES=["_CONSOLE","_CRT_SECURE_NO_WARNINGS","HAVE_CONFIG_H","PCRE_STATIC","SUPPORT_UCP","SUPPORT_UTF8","PSAPI_VERSION=1" ] )
 
     #env.Append( CPPFLAGS='  /Yu"pch.h" ' ) # this would be for pre-compiled headers, could play with it later
 
diff --git a/db/instance.cpp b/db/instance.cpp
index 60a80cdad96..d4455cec2c7 100644
--- a/db/instance.cpp
+++ b/db/instance.cpp
@@ -71,7 +71,7 @@ namespace mongo {
     KillCurrentOp killCurrentOp;
 
     int lockFile = 0;
-#ifdef WIN32
+#ifdef _WIN32
     HANDLE lockFileHandle;
 #endif
 
@@ -782,7 +782,7 @@ namespace mongo {
             /* This ought to be an unlink(), but Eliot says the last
                time that was attempted, there was a race condition
                with acquirePathLock().  */
-#ifdef WIN32
+#ifdef _WIN32
             if( _chsize( lockFile , 0 ) )
                 log() << "couldn't remove fs lock " << getLastError() << endl;
             CloseHandle(lockFileHandle);
@@ -858,7 +858,7 @@ namespace mongo {
         ss << getpid() << endl;
         string s = ss.str();
         const char * data = s.c_str();
-#ifdef WIN32
+#ifdef _WIN32
         assert ( _write( fd, data, strlen( data ) ) );
 #else
         assert ( write( fd, data, strlen( data ) ) );
@@ -874,7 +874,7 @@ namespace mongo {
             oldFile = true;
         }
 
-#ifdef WIN32
+#ifdef _WIN32
         lockFileHandle = CreateFileA( name.c_str(), GENERIC_READ | GENERIC_WRITE,
             0 /* do not allow anyone else access */, NULL, 
             OPEN_ALWAYS /* success if fh can open */, 0, NULL );
@@ -945,7 +945,7 @@ namespace mongo {
 
             if (!errmsg.empty()) {
                 cout << errmsg << endl;
-#ifdef WIN32
+#ifdef _WIN32
                 CloseHandle( lockFileHandle );
 #else
                 close ( lockFile );
@@ -964,7 +964,7 @@ namespace mongo {
             uasserted(13597, "can't start without --journal enabled when journal/ files are present");
         }
 
-#ifdef WIN32
+#ifdef _WIN32
         uassert( 13625, "Unable to truncate lock file", _chsize(lockFile, 0) == 0);
         writePid( lockFile );
         _commit( lockFile );
diff --git a/db/instance.h b/db/instance.h
index 6bac3d432e2..7bf163eb6ae 100644
--- a/db/instance.h
+++ b/db/instance.h
@@ -151,7 +151,7 @@ namespace mongo {
     };
 
     extern int lockFile;
-#ifdef WIN32
+#ifdef _WIN32
     extern HANDLE lockFileHandle;
 #endif
     void acquirePathLock(bool doingRepair=false); // if doingRepair=true don't consider unclean shutdown an error
diff --git a/db/security_key.cpp b/db/security_key.cpp
index 1ea702127bd..eb6a026ee2a 100644
--- a/db/security_key.cpp
+++ b/db/security_key.cpp
@@ -41,7 +41,7 @@ namespace mongo {
             return false;
         }
 
-#if !defined(WIN32)
+#if !defined(_WIN32)
         // check permissions: must be X00, where X is >= 4
         if ((stats.st_mode & (S_IRWXG|S_IRWXO)) != 0) {
             log() << "permissions on " << filename << " are too open" << endl;
diff --git a/pch.h b/pch.h
index 81abbaedc41..15819e2af31 100644
--- a/pch.h
+++ b/pch.h
@@ -31,13 +31,6 @@
 # define _CRT_SECURE_NO_WARNINGS
 #endif
 
-// [dm] i am not sure why we need this.
-#if defined(WIN32)
-# ifndef _WIN32
-# define _WIN32
-# endif
-#endif
-
 #if defined(_WIN32)
 // for rand_s() usage:
 # define _CRT_RAND_S
diff --git a/util/concurrency/spin_lock.cpp b/util/concurrency/spin_lock.cpp
index 679159ac7bb..1811f15d4bd 100644
--- a/util/concurrency/spin_lock.cpp
+++ b/util/concurrency/spin_lock.cpp
@@ -72,7 +72,7 @@ namespace mongo {
     }
 
     void SpinLock::unlock() {
-#if defined(WIN32)
+#if defined(_WIN32)
         LeaveCriticalSection(&_cs);
 #elif defined(__USE_XOPEN2K)
         pthread_spin_unlock(&_lock);