The ID of my (Fibre, iSCSI, SAS) tape drive keeps changing every time I reboot my server.
Windows has a higher level API called the device plug and play driver that assigns the names like "\\.\Tape0". The default Windows settings query the attached devices and assign the device names in the order of response. Tape drives can respond slightly faster or slower each time they are quarried resulting in the assignment of different device names. In order to fix this issue, delete the tape library and tape drives and modify the Windows registry.
From KB 873337 (the hotfix mentioned is in SP1)
Locate and then click the following registry subkey:
On the Edit menu, point to New, and then click DWORD Value.
Type Persistence, and then press ENTER.
Right-click the Persistence registry entry, and then click Modify.
Type 1 in the Value data box, and then click OK.
Quit Registry Editor.
Restart the computer.
When you restart instead of "\\.\Tape0" the devices will be named "\\.\Tape65463" or similar based on their serial numbers.