Inquiry on CMS IntelliCAD 12.0 PE Plus Network installation

Our company just acquired CMS IntelliCAD 12.0 PE Plus Network - 3 Concurrent Users. I'm having a bit of trouble understanding how to make the license work on 3 separate PC's.
I managed to install it on 2 PC's of the 3 connected to our network but I had to enter the activation key both times, the PDF states that activating the license at one of the clients is enough but it didn't work for me. The 2 initial PC's still run Intellicad and don't show the 15 day trial pop-up. The third PC I tried it on won't activate the license even with the key... Did I miss a step? Do I have to uninstall and try again from scratch?
Also I think I missused NKLS since I installed it twice.. on the second PC as well as the first. Maybe this is the root of the problem.
Could I get a detailed explanation?
Thank you.

Re: Inquiry on CMS IntelliCAD 12.0 PE Plus Network installation

You can find detailed instructions on how to install the CMS IntelliCAD 12.x PE PLUS Network version at the download section of
Check the CMS IntelliCAD Installers or the Manuals & Instructions sections.

You'll need to run CMS IntelliCAD at client PCs as system administrator. Looks clear that you might have a Windows UAC settings issue on the machines as you only need to activate the license at one client PC.
If required, you may also need to control your LAN firewall to allow CMS IntelliCAD installations to reach CMS NKLS installed at the LAN server.