You'd think I'd decide to just throw it out and buy a new computer. No, I can't convince myself to do that. The disk is good. It boots. PCFix 2011 says the registry is in good order. Checkdisk didn't find anything wrong. What happened: A few months ago, I formatted the disk and restored the computer. After that, I purchased PCFix 2011. I downloaded a new CCleaner, Things worked well for several weeks. The computer was on at all times, updated regularly and Kaspersky was protecting it from viruses. Then, the rolling blackouts hit. No UPS. That's my fault. BUT, the computer wasn't damaged. Checkdisk still doesn't find anything wrong, PCFix 2011 still keeps the registry clean, but the computer wouldn't stay up for more than a few minutes. This morning I ordered a new power supply. Heck, I don't know why. I just did. I also ran the ccleaner for the first time in several weeks. It deleted over 1 gig of junk. Since then, the computer has run without trouble. That has been the longest stretch of time that the machine has run. The thing is, I can't imagine what what ccleaner would have found that would have been causing random reboots. At least I'll get a little bit of an upgrade to the power supply of this old computer. That can't hurt. Oh, and, I'll get a UPS.