How to enable RemoteFX for a Windows 7 machine
Solution 1:
According to https://cloudblogs.microsoft.com/enterprisemobility/2012/11/26/remotefx-features-for-windows-8-and-windows-server-2012/, you should be able to access rich content on Windows 7 Enterprise if you install the RDP 8.0 content update.
Solution 2:
You cannot. RemoteFX was designed and built for servers hosting virtualized desktops. When Service Pack 1 for Windows 7 was released it contained an updated client that supports RemoteFX, however the host still needs to be a Windows 2008 R2 SP1 server.