I have to replace my tape library hardware. Should I, or do I need to, remove the current devices from BU Exec 12.0 before in install the new? I expect the wizard will install the new properly, not sure about removing the old one.
To be on the safer side, remove the device from the BE console.
Under devices tab, right click on the device and disable it, again right click on the device and delete it.
The installation wizard will configure the device. You may install the symantec driver for the tape drive by running the tapeinst.exe file from X:\Program Files\Symantec\Backup Exec.
Make sure the your medium changer (robotic arm ) is using the Microsoft drivers. If the robotic arm is configured to user Microsoft drivers then it will reflect as Unknow Medium Changer in the device manager.
Note: Symantec recommends Micorosoft driver for the medium changer and symantec drivers for the tape drive.
For more information on device & media refer to http://support.veritas.com/docs/255501