Crashed videocard?

Could be the video card, I've heard that 8800 GT's can die after a while. One fix is to bake it in the oven... lol. Anyway, I'd say either that or the PSU. Can you try a different GPU in there? Also, have you ever cleaned inside your case and heat sinks? They build up a lot of dust in even just 6 months. Get a compressed air duster and maybe a vacuum and clean everything you can. Especially if the GPU has a closed cover, you'll probably have to take it out and remove the cover then blow it out. I'm thinking this issue is probably over heating related, and so yeah it might be dead now. If it is, you can try the baking method just as a last resort otherwise looks like you'll be in the market for an upgrade.

What is your PSU? brand? model?
8800Gt is an old card, are you sure it's free from dust?
check the card temps? it could be an overheating...

Can you please supply your PSU brand and model, On top of that check for dust etc.
Using your computers onboard graphics update the cards drivers to the latest.

If it still doesn't go after this restart the computer and make sure the fan's running on the card. If not you either need to repair/replace the fan and see if that help's the problem or buy a new graphics card.

The power supply is a 375w Dell that came with the XPS. Don't see another brand listed on it. It is definitely a little dusty. The fan runs fine. No feed to monitor but the fan is at least running.

Just found out the min pcu requirements for the 8800gt is 400. Dust along with MW2 maxing out my system are, I think, probably the culprits behind my shut down. I just picked up a 9800GT for a low price and an Antec EarthWatts 650. Any thoughts?

Not the biggest GPU upgrade but it should all run well. With that PSU you have headroom for most single GPUs - say a GT 460 or a 5850 even 5870.

Yeah, I have a 9800GT in my system currently (until I upgrade to a 6xxx series) there decent these days, but nothing spectacular.

Should be able to play most games with decent settings, newer ones will have to have alot of there eyecandy disabled however.

I was considering the Radeon 5750, but decided to save myself the money for now and go with something I know my processor and motherboard can handle. Being tight on money influenced my decision some. Concerned more with having everything run properly than going with a solid upgrade at the moment. Thanks for your help guys! I'm about to install everything right now. Crossing my fingers.