I usually keep my computer on the entire day and only shut it down during the night. But once every time I boot my computer, it crashes and restarts itself. It usually happens 2-3 minutes after I've opened Firefox or some other program, but is not tied to any particular program. Also, it doesn't occur after that, only once. If I keep my computer running there are no problems, but this automatic restart crash is still annoying. I'm using two memories as of recently but my computer worked perfectly fine several months before it started having this problem. I have updated my BIOS, scanned for new drivers, my interior is not dusty or very hot and I have no USBs connected apart from my wireless adapter which has been there for a year now and not caused any problems. The crash is not a bluescreen, it just freezes the screen and it gets all pixely, and then it restarts. I'm using VIsta 32 by the way. Any help appreciated thanks.