I've cleaned the computer, reconnected the hard drive and RAM, did a chkdsk, defragged, whatever. I've had 2 crashes in the past 2 hours, and 6 in the past 3 days. Prior to last week, this computer had never had a blue screen. The error is just "has encountered a problem and shut down," no code, "less than equal to" or any such nonsense. Where do I start looking for the problem if this continues, which it probably will?