Not saying that this is the case at all in this situation, but I have a feeling that power spikes/drops have alot to do with alot of people's computer problems..
Funny that as I was reading this the power here went off and on a few times causing all manner of alarms and other assorted (I * E) nastyness. Thats why we all develop on Laptops, and everything has at least 1 power backup device between it and the mains. The
light were out but I was still reading Channel 9. I can say that singular precaution has saved me hours of work through the years.
On another note I have found that from time to time when windows is just plain acting squirrely and no amount of check this and check that seems to be fixing the problem. I will boot up a CD distro of Linux, ( like Knoppix ). On at least 3 occasions in the
past I have gotten Kernel Panics. Usually a sign of bad memory. The BIOS memory test is not worth the time it takes to run. Its a very simple test that has saved me hours of reinstall and repatch on at least 3 occasions in the past.