Hi Gert,
What is the Backup Exec version that you are using?
The Backup Exec Version 10.1 build 5629 is the latest version of Backup Exec.
* Start the installation over the existing installation. You need not uninstal the earlier version.
Symantec Backup Exec (tm) 10d rev. 5629 for Windows Servers Installation Files
http://support.veritas.com/docs/279332
Install the latest drivers also and then verify:
Symantec Backup Exec (tm) 10d (10.1.5629) - Device Driver Installer (20060815) - Includes Tape Driver Release (21) and Robotic Library Release (65) (Intel Only)
http://support.veritas.com/docs/284707
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