Hi!
You should do nothing special, the button must be visible when you connect to a Windows OS. We solved a similar problem in an old version, can you confirm that you’re using 4.3.30 also on Windows Server 2008R2?
If the installed version is the same on client and server, it would be helpful if you could send client side logs to issues[at]nomachine[dot]com. You can find them in the directory %USERPROFILE%\.nx\
