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

Answer: 
Or you could Right click on the window and select About
![enter image description here](https://i.stack.imgur.com/CvjyF.png)
There can be maybe better way with PowerShell.

First one need complete table of MSTSC build numbers and just compare to output of:

```
(Get-Item C:\Windows\System32\mstsc.exe).VersionInfo.FileVersion

```

And the second one is to read CLSID of registered components which contain also RDP binaries, like that:

```
$Current = 0
$GUID = Get-ChildItem -LiteralPath "Registry::HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID" | Select Name
$GUIDNum = Get-ChildItem -LiteralPath "Registry::HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID" | Select Name | Measure
While($Current -ne $GUIDNum.Count) {
$Path = $GUID[$Current] | Select -ExpandProperty Name
$GUIDName = ((get-itemproperty -literalpath "Registry::$Path").'(default)') 
If ($GUIDName -like 'Microsoft RDP Client Control (redistributable) - version*')
{
Write-Host $GUIDName
}
$Current++
}

```