[Edited by The Major O, 2/27/2011 1:43:09 PM]
You have to use one of the various undelete software apps out there, not one gives a 100% success as when a file is hard deleted the data has a chance to be overwriten by a new file.
Piriform Recuva -> Link
* Updated game trainers and cheats daily
* Get notified when new cheats are added
* Request which games get new trainers
* Priority support with any problem