You could always put your hard-drive in another computer, and back the files up that way, and then format and re-install later.
What I was about to say...
Also if you have your Windows install disc, you might try installing windows on a new partition and then once its working navigate to your files and burn em to a disc. Then you can reformat and install.
Surely making it a slave, and reformatting it would be the easier option?
In essence, could you not, slave it, format it, and install windows on it while it was still slaved in another rig, or does windows HAVE to be put on the C: drive? ...Or was that just DOS?
Urgh, back to the 500 page A+ Essentials book for me...
Yay(!)