This policy setting allows you to specify whether desktop composition is allowed for remote desktop sessions. This policy setting does not apply to RemoteApp sessions.Desktop composition provides the user interface elements of Windows Aero such as translucent windows for remote desktop sessions. Because Windows Aero requires additional system and bandwidth resources allowing desktop composition for remote desktop sessions can reduce connection performance particularly over slow links and increase the load on the remote computer. If you enable this policy setting desktop composition will be allowed for remote desktop sessions. On the client computer you can configure desktop composition on the Experience tab in Remote Desktop Connection (RDC) or by using the "allow desktop composition" setting in a Remote Desktop Protocol (.rdp) file. In addition the client computer must have the necessary hardware to support Windows Aero features.Note: Additional configuration might be necessary on the remote computer to make Windows Aero features available for remote desktop sessions. For example the Desktop Experience feature must be installed on the remote computer and the maximum color depth on the remote computer must be set to 32 bits per pixel. Also the Themes service must be started on the remote computer.If you disable or do not configure this policy setting desktop composition is not allowed for remote desktop sessions even if desktop composition is enabled in RDC or in the .rdp file.
Windows Components\Remote Desktop Services\Remote Desktop Session Host\Remote Session Environment
Machine
Windows Server 2008 R2 only
HKLM\SOFTWARE\Policies\Microsoft\Windows NT\Terminal Services!fAllowDesktopCompositionOnServer
Terminalserver-Server.admx