Hi Dronetek !
You could try a repair install.
Boot on the XP CD. You'll need to change the boot order to CD-rom first in the bios (you access the bios by repeatedly pressing a key during startup, it's usually the del but search for a message telling you which key to press if that doesn't work).
When prompted to do so, press a key to boot on the CD. Then choose to "setup Windows now", accept the license agreement, select the partition Windows is currently installed on and press 'R' to repair your current installation. Make sure the option you get is to "repair your current installation" before going further.
You shouldn't loose any files during the process but you'll have to redo all the latest critical updates on windows update. Some programs may stop working, in which case you'll have to reinstall them.
Check this link should you encounter any problem. Actually, I recommend you read it before starting the repair install, to be wiser from the start :
http://www.michaelstevenstech.com/XPrepairinstall.htm