To prevent a user from logging in, disable their login id. (If you delete their login id, the change log history for that user will also be deleted.)
- Go to Admin > Users.
- In the User Name column, click on the User Name you want to modify and select Edit User 'user name'. Near the bottom of the dialog box is a check-box labeled Disabled.
- To Disable - Click in the check-box so that a check mark is displayed. The next time this user attempts to login, the message "This account has been disabled by the administrator" will display and the user will be denied access.
- To Re-enable - Click in the check-box so that the check mark is removed.