Hi Greg,
If you stored the Project file on your computer and didn't back it up
yourself, there is no backup copy. If this is the case, I'm afraid you have
learned about backing up important files the hard way.
If you stored the project file on a networked server, it's possible the file
was backed up by the folks in your IS department. If you stored the file on
the server, I would check with your network people and see if they can
recover your file from their backup.
Good luck and let us know if we can assist any further.
Julie