today I installed on VM Windows 10 Enterprise OS.
I added it to existing Active Directory.
I created a localadmins group in AD with rights to install software.
I created a localadmin user and added it to the localadmins group.
I logged into Windows 10 with the localadmin user and installed NoMachine 8.4.2 from http://www.nomachine.com.
After restarting Windows 10, I can connect to this desktop, I see the NoMachine icon in the tray.
Everything works without a problem.
Your problem seems to be related to your machine configuration or premissions in the GPO.
You should discuss this issue with your company administrators.