Disappearing files!

I recently had to reinstall Windows XP on my computer, and I did so without formatting my Hard Drive. The installation went fine until i actually got to my desktop. There were no icons, no programs or applications installed or anything. It was exactly as though I HAD formatted my Hard Drive. The only thing is, according to My Computer 100GB of my Hard Drive is taken up...exactly the same amount as was taken up before I reinstalled Windows. Basically my old files are on my Hard Drive somewhere, but I can't find them. I have looked in every folder i can find, including hidden folders but they are nowhere to be found.

Can anyone give me any ideas as to where my files might be?!

Thankyou for any help.

 

I'm not sure if you will be able to locate your files they normally would be viewable if u just reisntalled with out formatting, however there are programs out there to recover lost data but they cost money

http://www.winundelete.com/?rid=google&kid=wu0801
http://www.smartundelete.com/
http://www.recovermyfiles.com/

This side looks good has free appcations:
http://www.pcworld.com/downloads/collection/collid,1295-order,1-c,downloads/files.html