diff --git a/reactos/subsystems/win32/win32k/ntuser/class.c b/reactos/subsystems/win32/win32k/ntuser/class.c
index 4ee8891e962..fd8a0ba73f9 100644
--- a/reactos/subsystems/win32/win32k/ntuser/class.c
+++ b/reactos/subsystems/win32/win32k/ntuser/class.c
@@ -16,8 +16,7 @@
  *  along with this program; if not, write to the Free Software
  *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
-/* $Id$
- *
+/*
  * COPYRIGHT:        See COPYING in the top level directory
  * PROJECT:          ReactOS kernel
  * PURPOSE:          Window classes
@@ -1855,7 +1854,7 @@ UserRegisterSystemClasses(IN ULONG Count,
                                pi);
         if (Class != NULL)
         {
-            Class->ClassId = SystemClasses[i].ClassId;
+            Class->fnID = SystemClasses[i].ClassId;
 
             ASSERT(Class->System);
             Class->Next = pi->SystemClassList;
@@ -1986,6 +1985,111 @@ InvalidParameter:
 }
 
 
+RTL_ATOM
+NTAPI
+NtUserRegisterClassExWOW(
+    WNDCLASSEXW* lpwcx,
+    PUNICODE_STRING ClassName,
+    PUNICODE_STRING ClsNVersion,
+    PCLSMENUNAME pClassMenuName,
+    DWORD fnID,
+    DWORD Flags,
+    LPDWORD pWow)
+{
+    WNDCLASSEXW CapturedClassInfo = {0};
+    UNICODE_STRING CapturedName = {0}, ClassnametoVersion = {0};
+    RTL_ATOM Ret = (RTL_ATOM)0;
+
+    UserEnterExclusive();
+
+    _SEH_TRY
+    {
+        /* Probe the parameters and basic parameter checks */
+        if (ProbeForReadUint(&lpwcx->cbSize) != sizeof(WNDCLASSEXW))
+        {
+            goto InvalidParameter;
+        }
+        if (!pClassMenuName)
+        {
+            goto InvalidParameter;
+        }
+
+        ProbeForRead(lpwcx,
+                     sizeof(WNDCLASSEXW),
+                     sizeof(ULONG));
+        RtlCopyMemory(&CapturedClassInfo,
+                      lpwcx,
+                      sizeof(WNDCLASSEXW));
+        /*
+          Need to watch this. When UnregisterClass is called these pointers
+          are freed by the caller in user space. So, we just probe the data
+          for now and pass it on and copy it to the shared class structure.
+         */
+        ProbeForRead(pClassMenuName,
+                     sizeof(CLSMENUNAME),
+                     sizeof(ULONG));
+
+        CapturedName = ProbeForReadUnicodeString(ClassName);
+        ClassnametoVersion = ProbeForReadUnicodeString(ClsNVersion);
+
+        if (CapturedName.Length & 1 || ClassnametoVersion.Length & 1 ||
+            CapturedClassInfo.cbClsExtra < 0 ||
+            CapturedClassInfo.cbClsExtra + CapturedName.Length +
+                ClassnametoVersion.Length + sizeof(WINDOWCLASS) < CapturedClassInfo.cbClsExtra ||
+            CapturedClassInfo.cbWndExtra < 0 ||
+            CapturedClassInfo.hInstance == NULL)
+        {
+            goto InvalidParameter;
+        }
+
+        if (CapturedName.Length != 0)
+        {
+            ProbeForRead(CapturedName.Buffer,
+                         CapturedName.Length,
+                         sizeof(WCHAR));
+        }
+        else
+        {
+            if (!IS_ATOM(CapturedName.Buffer))
+            {
+                goto InvalidParameter;
+            }
+        }
+
+        if (ClassnametoVersion.Length != 0)
+        {
+            ProbeForRead(ClassnametoVersion.Buffer,
+                         ClassnametoVersion.Length,
+                         sizeof(WCHAR));
+        }
+        else if (ClassnametoVersion.Buffer != NULL &&
+                 !IS_INTRESOURCE(ClassnametoVersion.Buffer))
+        {
+InvalidParameter:
+            SetLastWin32Error(ERROR_INVALID_PARAMETER);
+            _SEH_LEAVE;
+        }
+
+        /* Register the class */
+//        Ret = UserRegisterClass(&CapturedClassInfo,
+//                                &CapturedName,
+//                                &ClassnametoVersion,
+//                                hMenu, /* FIXME - pass pointer */
+//                                wpExtra,
+//                                Flags);
+
+    }
+    _SEH_HANDLE
+    {
+        SetLastNtError(_SEH_GetExceptionCode());
+    }
+    _SEH_END;
+
+    UserLeave();
+
+    return Ret;
+}
+
 
 ULONG_PTR NTAPI
 NtUserGetClassLong(IN HWND hWnd,
@@ -2116,7 +2220,7 @@ NtUserSetClassWord(
 BOOL NTAPI
 NtUserUnregisterClass(IN PUNICODE_STRING ClassNameOrAtom,
                       IN HINSTANCE hInstance,
-                      DWORD Unknown)
+                      OUT PCLSMENUNAME pClassMenuName)
 {
     UNICODE_STRING CapturedClassName;
     BOOL Ret = FALSE;
diff --git a/reactos/subsystems/win32/win32k/ntuser/message.c b/reactos/subsystems/win32/win32k/ntuser/message.c
index da2a0a6fc16..1bec09fc327 100644
--- a/reactos/subsystems/win32/win32k/ntuser/message.c
+++ b/reactos/subsystems/win32/win32k/ntuser/message.c
@@ -1052,20 +1052,6 @@ CLEANUP:
    END_CLEANUP;
 }
 
-LRESULT STDCALL
-NtUserMessageCall(
-   HWND hWnd,
-   UINT Msg,
-   WPARAM wParam,
-   LPARAM lParam,
-   ULONG_PTR ResultInfo,
-   DWORD dwType,
-   BOOL Ansi)
-{
-   UNIMPLEMENTED
-
-   return 0;
-}
 
 static NTSTATUS FASTCALL
 CopyMsgToKernelMem(MSG *KernelModeMsg, MSG *UserModeMsg, PMSGMEMORY MsgMemoryEntry)
@@ -1846,6 +1832,82 @@ IntUninitMessagePumpHook()
    return FALSE;
 }
 
+/*
+   Win32k counterpart of User DefWindowProc
+ */
+LRESULT FASTCALL
+IntDefWindowProc(
+   PWINDOW_OBJECT Window,
+   UINT Msg,
+   WPARAM wParam,
+   LPARAM lParam)
+{
+   PWINDOW Wnd;
+
+   if (Msg > WM_USER) return 0;
+
+   Wnd = Window->Wnd;
+   if (!Wnd) return 0;
+
+   switch (Msg)
+   {
+      case WM_SHOWWINDOW:
+      {
+         if ((Wnd->Style & WS_VISIBLE) && wParam) break;
+         if (!(Wnd->Style & WS_VISIBLE) && !wParam) break;
+         if (!Window->hOwner) break;
+         if (LOWORD(lParam))
+         {
+            if (wParam)
+            {
+               if (!(Window->Flags & WIN_NEEDS_SHOW_OWNEDPOPUP)) break;
+               Window->Flags &= ~WIN_NEEDS_SHOW_OWNEDPOPUP;
+            }
+            else
+                Window->Flags |= WIN_NEEDS_SHOW_OWNEDPOPUP;
+
+            co_WinPosShowWindow(Window, wParam ? SW_SHOWNOACTIVATE : SW_HIDE);
+         }
+      }
+      break;
+   }
+
+   return 0;
+}
+
+
+LRESULT STDCALL
+NtUserMessageCall(
+   HWND hWnd,
+   UINT Msg,
+   WPARAM wParam,
+   LPARAM lParam,
+   ULONG_PTR ResultInfo,
+   DWORD dwType, // fnID?
+   BOOL Ansi)
+{
+   LRESULT lResult = 0;
+   PWINDOW_OBJECT Window = NULL;
+
+   UserEnterExclusive();
+
+   /* Validate input */
+   if (hWnd && (hWnd != INVALID_HANDLE_VALUE) && !(Window = UserGetWindowObject(hWnd)))
+   {
+      return 0;
+   }
+
+   switch(dwType)
+   {
+      case NUMC_DEFWINDOWPROC:
+         lResult = IntDefWindowProc(Window, Msg, wParam, lParam);
+      break;
+   }
+
+   UserLeave();
+   return lResult;
+}
+
 #define INFINITE 0xFFFFFFFF
 #define WAIT_FAILED ((DWORD)0xFFFFFFFF)
 
diff --git a/reactos/subsystems/win32/win32k/ntuser/ntstubs.c b/reactos/subsystems/win32/win32k/ntuser/ntstubs.c
index 58e1bf5ebb3..9622484c592 100644
--- a/reactos/subsystems/win32/win32k/ntuser/ntstubs.c
+++ b/reactos/subsystems/win32/win32k/ntuser/ntstubs.c
@@ -1,5 +1,4 @@
-/* $Id$
- *
+/*
  * COPYRIGHT:        See COPYING in the top level directory
  * PROJECT:          ReactOS kernel
  * PURPOSE:          Native User stubs
@@ -909,22 +908,6 @@ NtUserRealWaitMessageEx(
     return 0;
 }
 
-/* http://www.reactos.org/pipermail/ros-kernel/2003-November/000589.html */
-HWINSTA
-NTAPI
-NtUserRegisterClassExWOW(
-    CONST WNDCLASSEXW* lpwcx,
-    BOOL bUnicodeClass,
-    WNDPROC wpExtra,
-    DWORD dwUnknown4,
-    DWORD dwUnknown5,
-    DWORD dwUnknown6,
-    DWORD dwUnknown7)
-{
-    UNIMPLEMENTED;
-    return 0;
-}
-
 DWORD
 NTAPI
 NtUserRegisterUserApiHook(
diff --git a/reactos/subsystems/win32/win32k/ntuser/simplecall.c b/reactos/subsystems/win32/win32k/ntuser/simplecall.c
index 191f9e1c1ae..b6ee8ab9438 100644
--- a/reactos/subsystems/win32/win32k/ntuser/simplecall.c
+++ b/reactos/subsystems/win32/win32k/ntuser/simplecall.c
@@ -511,31 +511,6 @@ NtUserCallTwoParam(
          RETURN( (DWORD)IntShowOwnedPopups(Window, (BOOL) Param2));
       }
 
-      case TWOPARAM_ROUTINE_ROS_SHOWWINDOW:
-         {
-#define WIN_NEEDS_SHOW_OWNEDPOPUP (0x00000040)
-            DPRINT1("ROS_SHOWWINDOW\n");
-
-            if (!(Window = UserGetWindowObject((HWND)Param1)))
-            {
-               RETURN( 1 );
-            }
-
-            if (Param2)
-            {
-               if (!(Window->Flags & WIN_NEEDS_SHOW_OWNEDPOPUP))
-               {
-                  RETURN( -1 );
-               }
-               Window->Flags &= ~WIN_NEEDS_SHOW_OWNEDPOPUP;
-            }
-            else
-               Window->Flags |= WIN_NEEDS_SHOW_OWNEDPOPUP;
-
-            DPRINT1("ROS_SHOWWINDOW ---> 0x%x\n",Window->Flags);
-            RETURN( 0 );
-         }
-
       case TWOPARAM_ROUTINE_ROS_UPDATEUISTATE:
       {
           WPARAM wParam;
diff --git a/reactos/subsystems/win32/win32k/ntuser/window.c b/reactos/subsystems/win32/win32k/ntuser/window.c
index 7f4f55ab834..bc1a7ac23bb 100644
--- a/reactos/subsystems/win32/win32k/ntuser/window.c
+++ b/reactos/subsystems/win32/win32k/ntuser/window.c
@@ -4701,7 +4701,6 @@ CLEANUP:
    END_CLEANUP;
 }
 
-#define WIN_NEEDS_SHOW_OWNEDPOPUP (0x00000040)
 
 BOOL
 FASTCALL
@@ -4711,9 +4710,9 @@ IntShowOwnedPopups(PWINDOW_OBJECT OwnerWnd, BOOL fShow )
    PWINDOW_OBJECT pWnd;
    HWND *win_array;
 
-   ASSERT(OwnerWnd);
+//   ASSERT(OwnerWnd);
 
-   win_array = IntWinListChildren(OwnerWnd);//faxme: use desktop?
+   win_array = IntWinListChildren(UserGetWindowObject(IntGetDesktopWindow()));
 
    if (!win_array)
       return TRUE;