With the release of OTRS Help Desk 4, it seems that running OTRS on a native Windows environment for all intents and purposes is no longer viable. By killing off the Windows installer and recommending migration into the OTRS appliance, the OTRS Group seems to be subtly hinting that OTRS on Windows is dead in the water. The now unmaintaned OTRS Windows installer. Switching to the OTRS appliance might be a good solution for some Windows installations, but in my case OTRS is configured with MS Active Directory as a customer and agent backend, and we’re relaying on IIS for single sign on.