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.
Here's a PowerShell query you can use:

```
wmic datafile where name="C:\\windows\\system32\\mstsc.exe" get manufacturer, name, version

```