Question: Does any know how to get the RDP version Windows is running with?

Answer: 
Windows RDP uses the executable mstsc.exe located in c:\windows\system32

Simply right click on this file, and go to properties, then click the version tab.

hope this helps.
or you could also click Start > Run > mstsc and when you see the Remote Desktop Connection window appear, click the top left hand corner "computer" icon and select "About".