laptop monitor problem

I have a black rectangular box running on the right corner of my monitor, its about 1 inch wide and 6 inches long. My display contiues to run underneath and responds but I can't clear the box, any help, advice or suggestions would be much appreciated. I'm running a pentium2 400 on xp pro. 160mb of ram.

 

It's there even after you reboot? Is it there if you would attach an external monitor?

 

Yes on both. It's there after I reboot and when I connect an external monitor. The last time it wasn't there was prior to loading a video game "Command and Conquer." I removed the game but it didn't fix the problem.