If the disk is not physically damaged, there are software recovery tools available that should be able to help you out. Recuva has already been mentioned and it does a decent job, but my favourites are GetDataBack and Stellar Phoenix, there hasn't been much that got past those being able to recover any data that I needed back
Whatever else, do not write anything to the drive you are trying to recover from. I suggest making an image of the disk and working with that to recover your data, or if you absolutely have to use the disk, mount it as read only, but this would be my last resort, because it's all to easy to make further mistakes and cause more damage to your data, possibly putting it beyond reach of recovery.