Follow the series of steps for this events1) Work on "Filename.doc" for a long time, saving repeatedly. Close it.2) Open a new Word document and save it as "Filename.doc", then click "OK" when asked if you want to replace the document with the same name.If that's what happened... you're pretty much out of luck as far as I know. Your only hope would be to shut the computer down RIGHT NOW, then get a copy of FileSalvage (or a similar application like Data Rescue II) and use it to scan the drive in hopes that it can find remnants of the overwritten file. Hope is slim, though.If you had just deleted the entire contents of the document from within Word and hit "save", there might be some hope that Word left a temp file or "extraneous" data within the file itself. If you have "allow fast saves" checked in the preferences, the file might still contain some, if not all, of the data, although I'm not sure if there's any good way to get to it.If this is the case (and Undo doesn't help, of course), you might try Force-quitting Word (rather than a normal quit, so it doesn't have time to clean up any temp files or such), and hope that you can find the remaining temp file (it may automatically open it when you reopen Word, or it may be sitting in the same folder as the original document).You may want to post in more detail what happened, but whatever you do, DON'T do anything to the computer--the more you use it, the more likely that data is to get overwritten.