This policy setting allows you to restrict users to a single Remote Desktop Services session. The recommended state for this setting is: Enabled. Rationale: This setting ensures that users & administrators who Remote Desktop to a server will continue to use the same session - if they disconnect and reconnect, they will go back to the same session they were using before, preventing the creation of a second simultaneous session. This both prevents unnecessary resource usage by having the server host unnecessary additional sessions (which would put extra load on the server) and also ensures a consistency of experience for the user.
To establish the recommended configuration via GP, set the following UI path to Enabled: Computer Configuration\Policies\Administrative Templates\Windows Components\Remote Desktop Services\Remote Desktop Session Host\Connections\Restrict Remote Desktop Services users to a single Remote Desktop Services session Note: This Group Policy path is provided by the Group Policy template TerminalServer.admx/adml that is included with all versions of the Microsoft Windows Administrative Templates. Note #2: In older Microsoft Windows Administrative Templates, this setting was named Restrict Terminal Services users to a single remote session, but it was renamed starting with the Windows 7 & Server 2008 R2 Administrative Templates. Impact: None - this is the default behavior. Default Value: Enabled. (Users who log on remotely by using Remote Desktop Services will be restricted to a single session (either active or disconnected) on that server. If the user leaves the session in a disconnected state, the user automatically reconnects to that session at the next logon.)