Hello,
As mentioned by you in your reply on 31st May, "My Backup Exec service account is a domain admin however I need a user to be able to "maintain" the backup system by at least performing tape loading/unloading/erasing operations".
If it is so then the user you wish to use, give it Domain User rights. Please refer to the following technote to create a new user:
How to change the user name or password of the VERITAS Backup Exec Services Account in VERITAS Backup Exec (tm) 9.x for Windows Servers
http://support.veritas.com/docs/254246
Regards
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