You can disable and enable users on the local Active Directory domain using the User Control Console
To disable an existing user
1) Log into the User Control Console. (For details of how to access the User Control Console please see this article)
2) Click on the Users Tab at the top of the page
3) Click on the name of the user account you wish to disable
4) Click on the Edit button
5) Click on the Off/On button under Account Enabled to disable or enable the account
This will disable or enable the account in the local Active Directory.