You can change the account that the software uses to perform backup and restore operations to the local system account or to a specific account. For information about the required permissions, see User Account Configuration for the SQL Server Solution.
From the navigation pane, go to Protect > Databases.
The instances page appears.
Click the SQL Server instance that you want to modify.
The instance properties page appears.
In the General section, click Edit.
The Edit dialog box appears.
Select the account to use.
To use the system account, select Use local system account.
To use a specific account, select Impersonate user, and then in the Username and Password boxes, type the user credentials.
The software uses the updated credentials for the next backup operation or restore operation.