This policy setting allows you to configure graphics encoding to use the RemoteFX Codec on the Remote Desktop Session Host server so that the sessions are compatible with non-Windows thin client devices designed for Windows Server 2008 R2 SP1. These clients only support the Windows Server 2008 R2 SP1 RemoteFX Codec.If you enable this policy setting users' sessions on this server will only use the Windows Server 2008 R2 SP1 RemoteFX Codec for encoding. This mode is compatible with thin client devices that only support the Windows Server 2008 R2 SP1 RemoteFX Codec.If you disable or do not configure this policy setting non-Windows thin clients that only support the Windows Server 2008 R2 SP1 RemoteFX Codec will not be able to connect to this server. This policy setting applies only to clients that are using Remote Desktop Protocol (RDP) 7.1 and does not affect clients that are using other RDP versions.
Windows Components\Remote Desktop Services\Remote Desktop Session Host\Remote Session Environment
Machine
At least Windows Server 2012 Windows 8 or Windows RT
HKLM\SOFTWARE\Policies\Microsoft\Windows NT\Terminal Services!fEnableVirtualizedGraphics
TerminalServer.admx