Thanks, all who responded. But the problem has now become moot. I removed the drivers as advised, preparatory to installing Maximus Decim Native USB ver.2.2 (which, by the way, won't work with my ME system). When I plugged the device in a second time the drivers were reloaded and now it works fine. The drive, by the way, is an Ativa from Office Depot. I could never discover who makes it.