Random Bytes...

No indication that it's anything that affected data. Sounds like power supply - capacitors blow up much more than you might think - however...

Hard drives are cheap, data might not be. Take the hard drive out, buy a new 40gig for $100 or so, load it up with an OS and programs to get going immediately while taking your time to get the data back.

Boot up with knoppix (http://www.knoppix.org) or fire the drive up in another box to check or copy off the data if you're the least bit suspicious.

"Repairing" a corrupted drive (esp with windows) often does more harm than good. On a personal desktop, it's almost always prudent to consider the OS instance unrepairable, reload the OS on a new disk and restore the data from the existing one.

At the very least, it's common knowledge that Win systems collect all sorts of registry cruft and can benefit from an OS reload at least once a year on a heavily used machine.

Then if you care to keep using it, you have a backup or expansion drive (stick it in another machine on your home network and set up an rsync job between networked machines to save your butt the next time).