This site is one of the best sources of information on how to keep a Windows PC running, with many tips and tricks:

http://windowssecrets.com/

The Hiren Boot CD is a comprehensive toolbox in a CD. Recover files, scan for malware, change passwords, fix corrupted drives etc.
System won't boot and you need that manuscript? Use Hiren.
You forgot the password on the system sitting in the closet? Reset it with Hiren.

Information on the software contained on the CD: http://www.hiren.info/pages/bootcd

Download from here: http://www.hirensbootcd.org/download/

YouTube video on how to create the Hiren Boot CD: http://www.youtube.com/watch?v=3oXmwMIJLoo