Question

How do I determine the Remote Desktop Protocol version supported by a particular client?

Note that I am NOT asking for the ActiveX control version but the underlying protocol version. As examples from two machines I checked using Help->About (or just About in the case of Windows XP):

• On Windows 8, I do NOT want 6.2.9200, I want 8.0.
• On Windows XP, I do NOT want 6.0.6001, I want 6.1.

And I am not asking for the protocol version in use in a given session (which is what Determine Remote Desktop Protocol version programatically? is referring to) because we’re not in a session, we are validating a client’s configuration.

Thanks!

Answer 1

I eventually contact Microsoft about this question and the (somewhat amazing) answer I got back is as follows:

That string is hard-coded and not retrieved from the server or AX (in
fact mstsc.exe checks the build number of mstsax.dll before loading it
to make sure it is consistent with its own build number).

So I guess I will need to fall back on hard-coded OS version information – perhaps the mstsc.exe version. That’s yucky but I don’t see what choice I have.