Before you do anything, I would make a copy of that "Saved Document" file and put it some place where you won't lose it / mess it up accidentally (and it'd probably be best to put it into some other folder so that Microsoft Word or Windows doesn't automatically delete it either).
Anyway, if that file is not a .doc file (or .docx or whatever) then one of two things is going on. Either Microsoft Word saves the back-up as an exact copy of the original file but with a different file extension, or else Microsoft Word creates back-ups in an entirely different file format.
If the former, then all you need to do is rename the file. To do this you need to go into the folder, make sure the file extensions are visible (I think there's an option for that in the View menu), and then just right-click the file, choose Rename, and change its extension to .doc or whatever.
But if the latter then the back-up isn't actually a Microsoft Word document, and you will likely need some additional software to convert it. I do not know if such software exists or not, but as long as all the textual data is still there then there's certainly some way to convert it.