This is just to know if hidden somewhere there is an autosave feature for a file a person is working on . I have spent 3 weeks in developing something and by error I didn't save when I closed the file and I went back to a 2 weeks ago release ..what a mess.
If you work only on one application, per say Smath, back up as is to make sure you don't lose more work sheets. Use the Windows "Restore". It did work for me several times, minimilising the disaster.