This post walk through some common client/server scenarios and explain the technical details of what generates the “Unknown Publisher” [Part 1] dialog as well as what has to be done to hide it. Here’re some common scenarios and configurations that exist today so that you can better understand what your options are. Depending on your specific scenario, you may or may not have an option to hide the dialog, so it is important to know where your configuration fits in these scenarios.
Note: Server Operating System refers to the web server that is running either the Remote Desktop Web Connection in Windows Server 2003 or TS Web Access in Windows Server 2008.
Server Operating System: Windows Server 2003
Client Operating System: Windows XP or Windows Vista and you have NO control over the client machines
This scenario is one of the most common, and your only option for hiding the dialog in this scenario is to change your web page so that it sends a signed RDP file to the client. This scenario is also the one that creates the most confusion and frustration.[...]