Fathers computer crashing... Possibly video card

My dads laptop is crashing. It doesn't happen right away when you start the computer it takes 1 to 2 minutes. When it happens its like artifacting in a pc game, except the whole screen fills up with these artifacts and then it turns black.

I think the video card could possibly be overheating, because it takes a little bit for it to happen. I was thinking virus for a second, but I think its definetly the video card because of the artifacts. I'm going too open up the case to make sure theres no dust in there.

Any help would be appreciated.

Thanks

and to the second poster he isn't even playing any games, he's just on the desktop.Frag_grenade