The trial is not tied to the machine really, it is tied to the log in. You can install Roon on 4 different computers and change which is the server and which the client.
I really suggest you attempt to get Roon going first on Windows 10. Windows 2012 v2 is not a straight forward install especially with all the software that you have currently loaded. The forums have several threads on how to get it working, but it is not a “run install and point it at the music” install that Windows 10 would be in comparison.