In class, I performed a quick demonstration using Remote Desktop Services in Windows Server 2008 R2. I set up a Remote Desktop Server and applied a Group Policy that restricted the users that logged into this Remote Desktop Server to a single session. The policy was located at:
Computer Configuration / Policies / Administrative Templates / Windows Components / Remote Desktop Services / Remote Desktop Sessions / Connections / Restrict Remote Desktop Services users to a single Remote Desktop Services Session
Once this policy was enabled, users were restricted. To test what happens when they connect on two different clients, I use the Remote Desktop Connection on two separate Windows 7 clients. On the first connection, I created a folder on the desktop so we can confirm that a single session was being used. I connected on the second client, and we saw the desktop with the folder. I then went back to the first client and we were notified that the Remote Desktop Session was disconnected. Reconnected with the first client caused the second client to lose its connection.