Follow these steps to do a repair install which should preserve your data,
settings, and programs:
1. Insert the Windows XP CD into your computer's CD-ROM drive or DVD-ROM
drive.
2. Restart your computer. If you have to, change the BIOS settings to start
from
the CD-ROM drive or DVD-ROM drive, and then restart your computer again.
3. At the "Welcome to Setup" page, press ENTER.
4. Press F8 to accept the Licensing Agreement.
5. Use the arrow keys to select the installation of Windows XP that you want
to
repair, and then press R to start the automatic repair process.
6. When Setup is completed, activate Windows XP.
Note that you will need your Product Key for this procedure, so have it
handy before you begin.
How to Perform a Windows XP Repair Install
http://michaelstevenstech.com/XPrepairinstall.htm
