I’d not come across this tool before, but whilst checking the location of the sn.exe tool I spotted it and thought I’d see what it did.

So the clrver.exe can be run from the Visual Studio command prompt or found at a location where your SDK exists, for example

"%ProgramFiles%\\Microsoft SDKs\Windows\v8.0A\bin\NETFX 4.0 Tools\clrver.exe"

Just running clrver.exe without any arguments will tell you which versions of the CLR are installed on your machine, whilst using the switch -all will result in a list of applications/processes running using the .NET CLR and tells us the version they’re using. If you already know the process id (pid) you can use clrver 123 to list the .NET CLR version being used by pid 123.