Sorry to hear you are having trouble.
Is Fences node-locked license?
Each license is bound to a PC, and any number of users / accounts can use Fences on said PC, but there are not other requirements or restrictions.
Could it be installed on Windows Server R2 or later?
It should, yes. That said, it is always prudent to install the fully functional trial to see if it is going to work in your environment - with your policies:
Stardock Support Manager