Refresh Desktop with Delphi

Below is a code that can be used to merefresh desktop without having to press F5.

procedure TForm1.Button2Click(Sender: TObject); begin

1.    SendMessage(FindWindow('Progman','Program   Manager'),WM_COMMAND,$A065,0);

2.    winexec(Pchar('rundll32 user,repaintscreen'),sw_Show);

3.  end;