Horizon supports at most one desktop session and one application session per user on an RDS host. You must configure the RDS host to restrict users to a single session. For Windows Server 2012 R2, Windows Server 2016, or Windows Server 2019, you can restrict users to a single session in a group policy setting.


  1. In the folder Computer Configuration\Administrative Templates\Windows Components\Remote Desktop Services\Remote Desktop Session Host\Connections, Click Start > Administrative Tools > Remote Desktop Services > Remote Desktop Session Host Configuration.
  2. Enable the group policy setting Restrict Remote Desktop Services users to a single Remote Desktop Services session.

What to do next

Install Horizon Agent on the RDS host. See Install Horizon Agent on a Remote Desktop Services Host.
Caution: When a user launches an application, for example, a Web browser, it is possible for a user to gain access to the local drives on the RDS host that is hosting the application. This can happen if the application provides functions that cause Windows Explorer to run. Do not create published desktop pools and application pools on the same farm so that desktop sessions are not affected.