From: DeskNow Knowledge Base
http://www.desknow.com/kb/

Active Directory integration
http://www.desknow.com/kb/idx/5/007/article/
DeskNow version: 2.4 and later 

It is possible to make DeskNow use Active Directory to authenticate users.

In this way it is possible to keep user accounts and passwords in a central location, and when an user password is changed in the directory, it is automatically changed in DeskNow.

DeskNow can also create accounts on demand, if they exist in the Active Directory domain, and are not in the DeskNow user database yet.

When you remove an account from Active Directory, the account remains in DeskNow, but the user is prevented from logging in.

Important: the admin user of every domain, and all domains and communities, are not created automatically from ActiveDirectory, and their password is not looked up in Active Directory. This allows you to mantain control of the system even if AD becomes unavailable.

To configure DeskNow to use AD authentication, see the Administration and Configuration manual, at the section 'External Authentication'.