but first I need to tell you that if you are using the computer you are running a risk of the data files getting overwritten as the sectors the files are on have been marked by the file system as being available.

You might want to look at something like FileScavenger http://www.quetek.com/prod02.htm Which does not need to be installed and can be saved to and run from a Floppy, Data CD, or Flash Drive. You can download and run it as a demo to see how much of the files it can recover before buying any license.

Avanquest has a couple of file recovery utilities:
Data Recovery Professional $39.95
Smart Data Recovery $49.95

There are also several free file recovery utilities such as:
Pandora - http://www.pandorarecovery.com/
Recuva - http://www.piriform.com/recuva
PC Inspector - http://www.pcinspector.de/default.htm?language=1

and some more here -
http://www.thefreecountry.com/utilities/datarecovery.shtml