nService

nService is the best customer service and help desk software that runs on IIS. You can use it to set up your customer service and support Website, intranet IT help desk Website, facility management Website, and HR help desk Website.

Features include customer self service, knowledge management, service request management, call management, asset management, product management, service management, service billing, discussion forums and calendar. It integrates with email and Active Directory. Installation instructions are in the setup.htm in the free trial zip file.