Well, since I have a Knoppix Linux CD, I saw this and thought it might be a good idea.
For a Windows PC, if Windows gets toasted, you're in trouble. You can't get any of your files back without reformatting. One of the effects of viruses. I don't have as much to worry about due to having a Mac, but I still have a Windows PC.
The deal with Knoppix is that its small enough to fit the entire OS, uncompressed, on a CD. You can literally pop the CD in and turn on the computer, and it starts up in Knoppix, never installing ANYTHING on the hard drive. Turn it off, pop the CD out, it'll never know it was there.
It's also an excellent hacking tool, if you were able to get to someone's computer to do it, lol
Anyway, some guy shaved a bunch of stuff off of Windows and managed to cram it on a CD. You can download the disk image and burn it to a CD. If Windows gets trashed by a virus, pop in the CD, and you can start up in a stripped-down Windows, and still back up all your files and reach all your programs.
http://www.techtv.com/screensavers/windowstips/story/0,24330,3662519,00.html
I might do it when I have some time.