[ Laptops & Notebooks ] Open Question : Windows XP problem!!! HELP!!?

I recently installed WoW and had a major lag and ended up restarting my computer a few times. After the first time restarting it, i got a message saying something about my graphics card. I have a DELL latitude d600 which is about 5 years old so i think my graphics card is a little out-dated. The game worked fine until after about 20 minutes, then it would lag. After restarting my computer for the 3rd time, it wouldn't boot. I have windows XP and right before the loading screen SHOULD come up, the screen just goes black and stays like that. I tried doing a test and it said there was an error with my OS. Will i need to reinstall my OS? or is there an easier way to get my OS to boot?