Cant access scsi tape drive

There are typically some required ????.sys, scsi system files required for the tapeback up drive as well (are they loaded)?. The scsi tape back ups also usually come with their own windows software for backing up. I can't tell from your description about device manager if you're infuring all drivers are loaded. Be sure and try HP for windows backup software specific to your backup drive. Also since HP doesn't manufacture scsi controllers or backup devices themselves to my knowledge try to identify the manufacturer and get recommended software.