http://www.ehow.com/how_4910631_down...very-disk.html

If you're running Windows XP and your computer software crashes or becomes unusable, you may have to run Windows XP recovery to reestablish your software and make your computer usable once again. When purchased, many computers don't come with a Windows XP recovery disk, but you can download one for free. The Windows XP recovery disk holds almost all of the computer software and files that came loaded with your PC and can assist you in rebuilding your hard drive.

1
Place a formatted floppy disk in your floppy disk drive. Click on the "Download a Windows XP recovery disk from Microsoft" link in Resources below. Click "Download." Then click "Save." Find your floppy drive on the menu and click "OK."
2

Remove the floppy disk when the Windows XP recovery disk download is complete, and place it in the computer on which you need to use it.
3

Shut down your computer; then turn your computer back on. Your computer will automatically start up running on the Windows XP recovery disk, which will allow you to install Windows XP once again.