The Backup Exec System Logon Account (SLA) is created when you install Backup Exec. When the SLA is created, the user name and password match the credentials provided during install for the Backup Exec Services credentials. The owner of the SLA is the user that installed Backup Exec and is a common account by default. Common accounts are shared accounts that can be accessed by all users.
The Backup Exec System Logon Account may have access to most or all of your resources since it contains the Backup Exec Services credentials. If you want to make Backup Exec more secure, you can change the SLA to be a restricted account. You can also delete it after making another logon account the default. However, if you delete the SLA, the jobs in which it is used may fail. If the SLA is deleted, you can re-create it using the Logon Account Management dialog box.
More Information
Creating a new Backup Exec System Logon Account
Creating a Backup Exec logon account
Editing a Backup Exec logon account
Replacing a Backup Exec logon account
Deleting a Backup Exec logon account