As long as the amount of free space on your disk is large, there is a good chance of recovering the data. Windows only rewrites over the data if there is no "unused" free space remaining. But then still, complete recovery cannot be guaranteed.
Undelete trial version can scan for deleted files, so perhaps you could see if they are "available"? But without paying you cannot recover more than a few kb.
Thanks Rob for that link; I didn't know there was a free utility available
But never having used it I cannot give any advice on it. (And I'm a bit confused as to why they have called file extensions disk formats)
I suggest you try Rob's program first. If there's no joy, try Undelete.