HALF OF MY LAPTOP SCREEN IS GONE BLANK

My laptop was working fine this morning and when I tried to open a new tab in IE, half of the screen went blank. I rebooted the laptop but half of the screen is still blank and all the programs seem to running fine from what I could see from the other half.
Has anyone encountered this sort of problem before?
Or has anyone got an idea of the problem?

My laptop is a DELL INSPIRON 1501 running Windows XP Media Center 2005 and was only bought on 29/01/07. Unfortunately, the 3 months warranty ran out last month.
Thank you