First, quit using that machine - you're most likely only screwing up your files more and more the more you use the machine.
None of these are free, but the 1st 2 offer a trial version that will give you an idea whether the app thinks it can help:
Restore2000
GetDataBack
And, the grandaddy of 'em all, and IMO the 800 Pound Gorilla, my personal pick (note: no free trial - it works more often than it doesn't, and better than any of the others):
SpinRite
Now, I recommend whatever you use, you run it from
BartPE, and that you copy any critical data to removeable media - preferably an external hard drive.