The screen resolution might be wrong.
For XP Right click desktop and go to Settings. For vista and up Right click desktop and go to Screen Resolution.
Now here there should be a drop box next to Resolution. Click on that box and move the slider next to the settings that say (Reccommened) Next to it.
They will probably either 1920x1080 or 1366x768 or 1280x720 or 1440x900 should work if its a wide screen 16:9
For 16:10 Reccommened would probably be either 1920x1200, 1680x1050 or 1280x800
Then click Apply and see if that works. If it does great! Click Ok and your done! If it doesn't and the screen goes black just leave it. It will go back to how it was after 15 seconds. Then try something a little lower but that should work...