My computer is about 5 years old, and it started doing it on games it has been able to run for years. So far I've scanned for viruses, cleaned the disk, and defragged; none of them helped. There's been nothing removed or added hardware wise since it started and nothing big software wise (ie same virus scan and other continuously operational programs). I'm thinking the problem is something hardware wise, but it's really just a guess.
Thanks in advance for any help.