Had similar query from customer recently - the file has been in Alibre/Geomagic for ages. As the name suggests it is used to unregister the Excel Add-in (if you no longer wish to use it).
If you look at the 'last changed/edited' date for the file you will see some time in 2010.
If at all concerned just delete it, it isn't required for routine operation, it can always be reinstated by a re-install...