If you get a virus in Windows and can get to mcafee.com, they have a
free online virus scanner.
Corrupted hard drives bothered me for a while during the 10.2G WD hard drive days. Some of you may remember how awful those drives were... I had 2 fail on me with my computer I bought 5 years ago. They failed all the time on the computers I had to troubleshoot for my helpdesk.
When the drive is corrupted, you're usually SCREWED. It can cost a lot of money to recover data from the drive.