All Spectra libraries use generic device drivers or drivers that are provided with backup software packages. If you are connected to a Windows host, and you are using Microsoft Data Protection Manager (DPM), then you must use the Windows Medium Changer driver.
If you are using Veeam Backup software on a Windows host, you must use the Windows Medium Changer driver.
The following are links to downloadable tape drive driver files on their respective manufacturers' web sites. Download the driver for the type of tape drive your library has, and then install that driver on the server that writes data to the drive.
Win 2008 Medium Changer Driver - (also for Win 2012) DO NOT install this driver unless you have been instructed to do so by Support.