Try this:
With both monitors attached and operating, on your main screen, find a blank area and right click the mouse. A selection box should open up. The last item on the list should say "Properties". Click on properties. This should give you the "Display Properties" screen.
You should see images of 2 monitors, not just 1. If you see only 1 monitor, then you have the same problem I have. Your multi-display Video card somehow did not install properly. And I have absolutly no idea what to do about it.
