A. It is possible to disconnect any user using the "Remote Access Admin" utility:

  1. Start the Remote Access Admin utility (Start - Programs - Administrative Tools - Remote Access Admin)
  2. Select the domain or server in the main window
  3. From the Users menu select 'Active Users'
  4. Select the account you wish to disconnect and click the 'Disconnect User' button.
  5. Click OK to the confirmation

If you also wanted to revoke the users dial-in permission check the 'Revoke Remote Access Permission' check box from the dialog.