It depends upon what part is broken. If it's a broken header, you can usually fix it by simply opening the file in a hex editor and fixing the header. I do this all the time during forensic investigations. If it's broken data inside the file, then there is not much you can do. I normally use EnCase or similar tools for recovering deleted files. What filesystem was the file on? If it was NTFS and it wasn't overwritten, then you should have gotten a complete file. Unfortunately, most file recovery software tools don't recognize an overwritten file and just recover all the sectors associated with the file from the $BITMAP whether they have been reallocated for another file or not.