Once the display is connected, Open the display properties (Right click on the desktop and choose Properties for XP, or Personalize for Vista or 7. You can adjust the monitor settings from there. The second display has to be enabled first, regardless of how you connect it. Alternatively, if your keyboard has a Function (Fn) key, hit it, and the key for adjusting the display outputs (usually Fn + F5, or Fn + F7). Continue this until you have the desired display setup.