Problem
What rights does the Backup Exec service account need?
Solution
The username being supplied should be a part of the local administrators group.
Note: Due to security implementations in Microsoft Small Business Server, the service account must be Administrator.
Act as part of the operating system (Windows 2000 only)
Backup files and directories
Create a token object
Logon as a batch job (Windows 2008 and higher)
Logon as a service
Manage auditing and security log
Restore files and directories
Take ownership of files and other objects
Note: "Create a token object" right is not required in Backup Exec 2014 and higher.
Also make sure the Backup Exec service account is not added under:
Deny logon as a service
Deny logon as a batch
This is important because DENY takes precedence over allow.
The Backup Exec service account should be a part of the local administrators group.
Please contact your local server administrator to configure above mentioned rights or refer to the below given Microsoft website :
technet.microsoft.com/en-us/library/cc784323(v=ws.10).aspx
technet.microsoft.com/en-us/library/cc739028(v=WS.10).aspx
Please review https://www.veritas.com/support/en_US/article.000007290 for other rights required for each Agent / Option being used in Backup Exec.