diff --git a/win/rfb_win32/CurrentUser.cxx b/win/rfb_win32/CurrentUser.cxx
index 7562d29..21531de 100644
--- a/win/rfb_win32/CurrentUser.cxx
+++ b/win/rfb_win32/CurrentUser.cxx
@@ -98,7 +98,7 @@
     // Try to find the Shell Tray Icon window and take its token
     //   NB: This will only work under NT/2K (and later, but they're dealt with above)
     //   NB: If the shell is not running then this will return an Unsafe Null token.
-    EnumDesktops(GetProcessWindowStation(), enumDesktops, (LONG)&h);
+    EnumDesktops(GetProcessWindowStation(), enumDesktops, (LPARAM)&h);
     isSafe_ = (h != 0);
   } else {
     // Try to open the security token for the User-Mode process
diff --git a/win/rfb_win32/Dialog.cxx b/win/rfb_win32/Dialog.cxx
index 90e7075..70a5fb5 100644
--- a/win/rfb_win32/Dialog.cxx
+++ b/win/rfb_win32/Dialog.cxx
@@ -1,4 +1,5 @@
 /* Copyright (C) 2002-2005 RealVNC Ltd.  All Rights Reserved.
+ * Copyright (C) 2010 D. R. Commander.  All Rights Reserved.
  * 
  * This is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -106,13 +107,13 @@
 
 
 
-BOOL CALLBACK Dialog::staticDialogProc(HWND hwnd, UINT msg,
+INT_PTR CALLBACK Dialog::staticDialogProc(HWND hwnd, UINT msg,
 				       WPARAM wParam, LPARAM lParam)
 {
   if (msg == WM_INITDIALOG)
-    SetWindowLong(hwnd, GWL_USERDATA, (LONG)lParam);
+    SetWindowLongPtr(hwnd, GWLP_USERDATA, lParam);
 
-  LONG self = GetWindowLong(hwnd, GWL_USERDATA);
+  LONG_PTR self = GetWindowLongPtr(hwnd, GWLP_USERDATA);
   if (!self) return FALSE;
 
   return ((Dialog*)self)->dialogProc(hwnd, msg, wParam, lParam);
@@ -165,13 +166,13 @@
 }
 
 
-BOOL CALLBACK PropSheetPage::staticPageProc(HWND hwnd, UINT msg,
+INT_PTR CALLBACK PropSheetPage::staticPageProc(HWND hwnd, UINT msg,
 				       WPARAM wParam, LPARAM lParam)
 {
   if (msg == WM_INITDIALOG)
-    SetWindowLong(hwnd, GWL_USERDATA, ((PROPSHEETPAGE*)lParam)->lParam);
+    SetWindowLongPtr(hwnd, GWLP_USERDATA, ((PROPSHEETPAGE*)lParam)->lParam);
 
-  LONG self = GetWindowLong(hwnd, GWL_USERDATA);
+  LONG_PTR self = GetWindowLongPtr(hwnd, GWLP_USERDATA);
   if (!self) return FALSE;
 
   return ((PropSheetPage*)self)->dialogProc(hwnd, msg, wParam, lParam);
diff --git a/win/rfb_win32/Dialog.h b/win/rfb_win32/Dialog.h
index 9784ba4..cb23baf 100644
--- a/win/rfb_win32/Dialog.h
+++ b/win/rfb_win32/Dialog.h
@@ -1,4 +1,5 @@
 /* Copyright (C) 2002-2005 RealVNC Ltd.  All Rights Reserved.
+ * Copyright (C) 2010 D. R. Commander.  All Rights Reserved.
  * 
  * This is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -87,7 +88,7 @@
       void enableItem(int id, bool state);
 
     protected:
-      static BOOL CALLBACK staticDialogProc(HWND hwnd, UINT msg,
+      static INT_PTR CALLBACK staticDialogProc(HWND hwnd, UINT msg,
 			      WPARAM wParam, LPARAM lParam);
       virtual BOOL dialogProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam);
       HINSTANCE inst;
@@ -145,7 +146,7 @@
 
     protected:
       void setPropSheet(PropSheet* ps) {propSheet = ps;};
-      static BOOL CALLBACK staticPageProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam);
+      static INT_PTR CALLBACK staticPageProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam);
       virtual BOOL dialogProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam);
       PROPSHEETPAGE page;
       PropSheet* propSheet;
diff --git a/win/rfb_win32/MsgWindow.cxx b/win/rfb_win32/MsgWindow.cxx
index 1f2299e..4c50c2f 100644
--- a/win/rfb_win32/MsgWindow.cxx
+++ b/win/rfb_win32/MsgWindow.cxx
@@ -1,4 +1,5 @@
 /* Copyright (C) 2002-2005 RealVNC Ltd.  All Rights Reserved.
+ * Copyright (C) 2010 D. R. Commander.  All Rights Reserved.
  * 
  * This is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -46,10 +47,10 @@
   LRESULT result = 0;
 
   if (msg == WM_CREATE)
-    SetWindowLong(wnd, GWL_USERDATA, (long)((CREATESTRUCT*)lParam)->lpCreateParams);
+    SetWindowLongPtr(wnd, GWLP_USERDATA, (LONG_PTR)((CREATESTRUCT*)lParam)->lpCreateParams);
   else if (msg == WM_DESTROY)
-    SetWindowLong(wnd, GWL_USERDATA, 0);
-  MsgWindow* _this = (MsgWindow*) GetWindowLong(wnd, GWL_USERDATA);
+    SetWindowLongPtr(wnd, GWLP_USERDATA, 0);
+  MsgWindow* _this = (MsgWindow*) GetWindowLongPtr(wnd, GWLP_USERDATA);
   if (!_this) {
     vlog.info("null _this in %x, message %x", wnd, msg);
     return SafeDefWindowProc(wnd, msg, wParam, lParam);