You can disable a user account at the user or user setting level. If you disable a user setting level, you will disable all users in that level.
Start the Administrator Interface and connect to the server.
At the bottom of the left pane, click the Server tab.
In the left window, expand a server group, server, User Setting Levels, and the user setting level with the user you want to disable.
Select the user you want to disable.
Click the Main tab.
Click the Enable this user account check box until it is white and empty.
Click Apply. A red "X" will appear over the user.
Start the Administrator Interface and connect to the server.
At the bottom of the left pane, click the Server tab.
In the left window, expand a server group, server, and User Setting Levels.
Select the User Setting Level you want to disable.
Click the Main tab.
Clear the Enable this settings level check box.
Click Apply. A red "X" will appear over the User Setting Level and any users that have not been enabled independently of the setting level.