I think it's most likely the DVD Drive? I mean it's not even recognizing most DVDs at all. Although it does play SOME DVDs, soit's like russian roulette, I mean it'll play one of every five or something!
I also need to just reinstall windows anyway, or get a new computer. For instance, I also can't move music from iTunes to my iPhone -- never have been able to since I got the phone in September. After 100 hours on the phone w/ various tech support people from various companies, during which it never got corrected and I wanted to kill myself, I just gave up. So getting a new computer (or reinstalling windows) would definitely improve my life greatly!