My wife plays a lot of Japanese games and thus most of them are browser games, or are started through a browser. She seems to always have this issue of her PC randomly shutting down (not restarting) while she's playing. She may go most of a day without it shutting down or 30 mins. It never turns off when she is doing anything else, just games. I just put in a new 450 power supply that I had lying around to see if that would fix the issue, but it didn't. I even put a new power cord. Now, I've heard overheating could be an issue, but I'm not sure if that is her issue. One thing that I predict it could be (but am unsure exactly how it works) is RAM (If this is null point, then it's likely a heating issue). I don't think she has any additional RAM in her PC and she is running W7Ultimate. I know you want specs usually, but she is on it atm, and I'll have to wait til later tonight to actually give you specs, but I'd really like to just get some brainstormed ideas on what I could/should check as an issue. Thank you, and I'll update this with specs/etc when I get the chance. May be a little difficult though, since her software is all in Japanese.