I have had and continue to use Hauptwerk V 4.1 for many years. Don't need to upgrade as I am just a lowly amateur who enjoys an occasional romp on the keyboard. Everything worked fine since my last usage (Nov.3), but yesterday the dongle ceased to function. My PC Device Mgr states there are NO DRIVERS installed for this unit. This dongle works OK on another backup PC. How can I get the drivers reinstalled in my present PC? Thanks