Excel For Osx Creating Unwanted Duplicate Files


I am running OSX 10.1.5 and Microsoft Excel for Mac. Each time I create a new file and then save it, I get another file saved in the same place with a name like "D1E74100" or "9820D100". I can trash the unwanted files without effecting the original file, but they take up space - why is this happening and how do I stop it???
Those are related tot he Auto-save feature.

Once you close the file, they'll go away.

...or you can disable the Auto-save feature in the prefrences.