function CreateInVisibleWindow(const WndClass: string; Method: TWndMethod): HWND;
var
 UtilWindowClass: TWndClass;

 function AllocateWnd(Method: TWndMethod): HWND;
 var
   TempClass: TWndClass;
   ClassRegistered: Boolean;
 begin
   UtilWindowClass.hInstance := HInstance;
 {$IFDEF PIC}
   UtilWindowClass.lpfnWndProc := @DefWindowProc;
 {$ENDIF}
   ClassRegistered := GetClassInfo(HInstance, UtilWindowClass.lpszClassName,
     TempClass);
   if not ClassRegistered or (TempClass.lpfnWndProc <> @DefWindowProc) then
   begin
     if ClassRegistered then
       Windows.UnregisterClass(UtilWindowClass.lpszClassName, HInstance);
     Windows.RegisterClass(UtilWindowClass);
   end;
   Result := CreateWindowEx(WS_EX_TOOLWINDOW, UtilWindowClass.lpszClassName,
     '', WS_POPUP {!0}, 0, 0, 0, 0, 0, 0, HInstance, nil);
   if Assigned(Method) then
     SetWindowLong(Result, GWL_WNDPROC, Longint(MakeObjectInstance(Method)));
 end;

begin
 with UtilWindowClass do
 begin
   style := 0;
   lpfnWndProc := @DefWindowProc;
   cbClsExtra := 0;
   cbWndExtra := 0;
   hInstance := 0;
   hIcon := 0;
   hCursor := 0;
   hbrBackground := 0;
   lpszMenuName := nil;
   lpszClassName := PChar(WndClass);
 end;

 Result := AllocateWnd(Method);

end;