diff --git a/reactos/lib/user32/windows/message.c b/reactos/lib/user32/windows/message.c
index f1cb86985e9..3b77990bb89 100644
--- a/reactos/lib/user32/windows/message.c
+++ b/reactos/lib/user32/windows/message.c
@@ -1,4 +1,4 @@
-/* $Id: message.c,v 1.45 2004/12/13 15:39:52 navaraf Exp $
+/* $Id: message.c,v 1.46 2004/12/25 20:30:49 navaraf Exp $
  *
  * COPYRIGHT:       See COPYING in the top level directory
  * PROJECT:         ReactOS user32.dll
@@ -190,6 +190,7 @@ MsgiUMToKMMessage(PMSG UMMsg, PMSG KMMsg, BOOL Posted)
           KMMsg->lParam = (LPARAM) DdeLparam;
         }
         break;
+
       case WM_DDE_EXECUTE:
         {
           SIZE_T Size;
@@ -217,6 +218,31 @@ MsgiUMToKMMessage(PMSG UMMsg, PMSG KMMsg, BOOL Posted)
           GlobalUnlock((HGLOBAL) UMMsg->lParam);
         }
         break;
+
+      case WM_COPYDATA:
+        {
+          PCOPYDATASTRUCT pUMCopyData = (PCOPYDATASTRUCT)UMMsg->lParam;
+          PCOPYDATASTRUCT pKMCopyData;
+
+          pKMCopyData = HeapAlloc(GetProcessHeap(), 0,
+                                  sizeof(COPYDATASTRUCT) + pUMCopyData->cbData);
+          if (pKMCopyData == NULL)
+            {
+              SetLastError(ERROR_OUTOFMEMORY);
+              return FALSE;
+            }
+
+          pKMCopyData->dwData = pUMCopyData->dwData;
+          pKMCopyData->cbData = pUMCopyData->cbData;
+          pKMCopyData->lpData = pKMCopyData + 1;
+
+          RtlCopyMemory(pKMCopyData + 1, pUMCopyData->lpData, 
+                        pUMCopyData->cbData);
+
+          KMMsg->lParam = (LPARAM)pKMCopyData;
+        }
+        break;
+
       default:
         break;
     }
@@ -231,6 +257,7 @@ MsgiUMToKMCleanup(PMSG UMMsg, PMSG KMMsg)
     {
       case WM_DDE_ACK:
       case WM_DDE_EXECUTE:
+      case WM_COPYDATA:
         HeapFree(GetProcessHeap(), 0, (LPVOID) KMMsg->lParam);
         break;
       default:
@@ -322,6 +349,13 @@ MsgiKMToUMMessage(PMSG KMMsg, PMSG UMMsg)
         }
         break;
 
+      case WM_COPYDATA:
+        {
+          PCOPYDATASTRUCT pKMCopyData = (PCOPYDATASTRUCT)KMMsg->lParam;
+          pKMCopyData->lpData = pKMCopyData + 1;
+        }
+        break;
+
       default:
         break;
     }
diff --git a/reactos/subsys/win32k/ntuser/message.c b/reactos/subsys/win32k/ntuser/message.c
index 7f5ea4fe9f1..49ae78eb52d 100644
--- a/reactos/subsys/win32k/ntuser/message.c
+++ b/reactos/subsys/win32k/ntuser/message.c
@@ -16,7 +16,7 @@
  *  along with this program; if not, write to the Free Software
  *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
-/* $Id: message.c,v 1.76 2004/12/11 19:39:18 weiden Exp $
+/* $Id: message.c,v 1.77 2004/12/25 20:30:50 navaraf Exp $
  *
  * COPYRIGHT:        See COPYING in the top level directory
  * PROJECT:          ReactOS kernel
@@ -81,6 +81,7 @@ static MSGMEMORY MsgMemory[] =
     { WM_SETTEXT, MMS_SIZE_LPARAMSZ, MMS_FLAG_READ },
     { WM_STYLECHANGED, sizeof(STYLESTRUCT), MMS_FLAG_READ },
     { WM_STYLECHANGING, sizeof(STYLESTRUCT), MMS_FLAG_READWRITE },
+    { WM_COPYDATA, MMS_SIZE_SPECIAL, MMS_FLAG_READ },
     { WM_WINDOWPOSCHANGED, sizeof(WINDOWPOS), MMS_FLAG_READ },
     { WM_WINDOWPOSCHANGING, sizeof(WINDOWPOS), MMS_FLAG_READWRITE },
   };
@@ -149,6 +150,9 @@ MsgMemorySize(PMSGMEMORY MsgMemoryEntry, WPARAM wParam, LPARAM lParam)
           return wParam ? sizeof(NCCALCSIZE_PARAMS) + sizeof(WINDOWPOS) : sizeof(RECT);
           break;
 
+        case WM_COPYDATA:
+          return sizeof(COPYDATASTRUCT) + ((PCOPYDATASTRUCT)lParam)->cbData;
+
         default:
           assert(FALSE);
           return 0;
diff --git a/reactos/subsys/win32k/ntuser/window.c b/reactos/subsys/win32k/ntuser/window.c
index 054e2ddfd09..b615e0688a9 100644
--- a/reactos/subsys/win32k/ntuser/window.c
+++ b/reactos/subsys/win32k/ntuser/window.c
@@ -16,7 +16,7 @@
  *  along with this program; if not, write to the Free Software
  *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
-/* $Id: window.c,v 1.257 2004/12/13 00:11:59 weiden Exp $
+/* $Id: window.c,v 1.258 2004/12/25 20:30:50 navaraf Exp $
  *
  * COPYRIGHT:        See COPYING in the top level directory
  * PROJECT:          ReactOS kernel
@@ -2273,7 +2273,7 @@ NtUserFillWindow(DWORD Unknown0,
 HWND FASTCALL
 IntFindWindow(PWINDOW_OBJECT Parent,
               PWINDOW_OBJECT ChildAfter,
-              PWNDCLASS_OBJECT ClassObject,
+              RTL_ATOM ClassAtom,
               PUNICODE_STRING WindowName)
 {
   BOOL CheckWindowName;
@@ -2305,11 +2305,8 @@ IntFindWindow(PWINDOW_OBJECT Parent,
       /* Do not send WM_GETTEXT messages in the kernel mode version!
          The user mode version however calls GetWindowText() which will
          send WM_GETTEXT messages to windows belonging to its processes */
-      if(((!CheckWindowName || (CheckWindowName && !RtlCompareUnicodeString(WindowName, &(Child->WindowName), FALSE))) &&
-          (!ClassObject || (ClassObject && (Child->Class == ClassObject))))
-         ||
-         ((!CheckWindowName || (CheckWindowName && !RtlCompareUnicodeString(WindowName, &(Child->WindowName), FALSE))) &&
-          (!ClassObject || (ClassObject && (Child->Class == ClassObject)))))
+      if((!CheckWindowName || !RtlCompareUnicodeString(WindowName, &(Child->WindowName), FALSE)) &&
+         (!ClassAtom || Child->Class->Atom == ClassAtom))
       {
         Ret = Child->Self;
         IntReleaseWindowObject(Child);
@@ -2358,8 +2355,7 @@ NtUserFindWindowEx(HWND hwndParent,
   UNICODE_STRING ClassName, WindowName;
   NTSTATUS Status;
   HWND Desktop, Ret = NULL;
-  PWNDCLASS_OBJECT ClassObject = NULL;
-  BOOL ClassFound;
+  RTL_ATOM ClassAtom;
   
   Desktop = IntGetCurrentThreadDesktopWindow();
   
@@ -2427,25 +2423,38 @@ NtUserFindWindowEx(HWND hwndParent,
   
   /* find the class object */
   if(ClassName.Buffer)
-  {
-    /* this expects the string in ClassName to be NULL-terminated! */
-    ClassFound = ClassReferenceClassByNameOrAtom(&ClassObject, ClassName.Buffer, NULL);
-    if(!ClassFound)
     {
-      if (IS_ATOM(ClassName.Buffer))
-        DPRINT1("Window class not found (%lx)\n", (ULONG_PTR)ClassName.Buffer);
-      else
-        DPRINT1("Window class not found (%S)\n", ClassName.Buffer);
-      SetLastWin32Error(ERROR_FILE_NOT_FOUND);
-      goto Cleanup;
-    }
+      PWINSTATION_OBJECT WinStaObject;
+
+      if (PsGetWin32Thread()->Desktop == NULL)
+        {
+          SetLastWin32Error(ERROR_INVALID_HANDLE);
+          goto Cleanup;
+        }
+
+      WinStaObject = PsGetWin32Thread()->Desktop->WindowStation;
+
+      Status = RtlLookupAtomInAtomTable(
+         WinStaObject->AtomTable,
+         ClassName.Buffer,
+         &ClassAtom);
+
+      if (!NT_SUCCESS(Status))
+        {
+          DPRINT1("Failed to lookup class atom!\n");
+          SetLastWin32Error(ERROR_CLASS_DOES_NOT_EXIST);
+          goto Cleanup;
+        }
   }
   
   if(Parent->Self == Desktop)
   {
     HWND *List, *phWnd;
     PWINDOW_OBJECT TopLevelWindow;
-    BOOL CheckWindowName;
+    BOOLEAN CheckWindowName;
+    BOOLEAN CheckClassName;
+    BOOLEAN WindowMatches;
+    BOOLEAN ClassMatches;
     
     /* windows searches through all top-level windows if the parent is the desktop
        window */
@@ -2461,6 +2470,7 @@ NtUserFindWindowEx(HWND hwndParent,
       }
       
       CheckWindowName = WindowName.Length > 0;
+      CheckClassName = ClassName.Buffer != NULL;
       
       /* search children */
       while(*phWnd)
@@ -2473,18 +2483,19 @@ NtUserFindWindowEx(HWND hwndParent,
         /* Do not send WM_GETTEXT messages in the kernel mode version!
            The user mode version however calls GetWindowText() which will
            send WM_GETTEXT messages to windows belonging to its processes */
-        if(((!CheckWindowName || (CheckWindowName && !RtlCompareUnicodeString(&WindowName, &(TopLevelWindow->WindowName), FALSE))) &&
-            (!ClassObject || (ClassObject && (TopLevelWindow->Class == ClassObject))))
-           ||
-           ((!CheckWindowName || (CheckWindowName && !RtlCompareUnicodeString(&WindowName, &(TopLevelWindow->WindowName), FALSE))) &&
-            (!ClassObject || (ClassObject && (TopLevelWindow->Class == ClassObject)))))
+        WindowMatches = !CheckWindowName || !RtlCompareUnicodeString(
+                        &WindowName, &TopLevelWindow->WindowName, FALSE);
+        ClassMatches = !CheckClassName ||
+                       ClassAtom == TopLevelWindow->Class->Atom;
+
+        if (WindowMatches && ClassMatches)
         {
           Ret = TopLevelWindow->Self;
           IntReleaseWindowObject(TopLevelWindow);
           break;
         }
         
-        if(IntFindWindow(TopLevelWindow, NULL, ClassObject, &WindowName))
+        if (IntFindWindow(TopLevelWindow, NULL, ClassAtom, &WindowName))
         {
           /* window returns the handle of the top-level window, in case it found
              the child window */
@@ -2499,7 +2510,7 @@ NtUserFindWindowEx(HWND hwndParent,
     }
   }
   else
-    Ret = IntFindWindow(Parent, ChildAfter, ClassObject, &WindowName);
+    Ret = IntFindWindow(Parent, ChildAfter, ClassAtom, &WindowName);
   
 #if 0
   if(Ret == NULL && hwndParent == NULL && hwndChildAfter == NULL)
@@ -2511,17 +2522,12 @@ NtUserFindWindowEx(HWND hwndParent,
     
     if((MsgWindows = IntGetWindowObject(IntGetMessageWindow())))
     {
-      Ret = IntFindWindow(MsgWindows, ChildAfter, ClassObject, &WindowName);
+      Ret = IntFindWindow(MsgWindows, ChildAfter, ClassAtom, &WindowName);
       IntReleaseWindowObject(MsgWindows);
     }
   }
 #endif
   
-  if (ClassObject != NULL)
-  {
-    ClassDereferenceObject(ClassObject);
-  }
-  
   Cleanup:
   if(ClassName.Length > 0 && ClassName.Buffer)
     ExFreePool(ClassName.Buffer);