Registry location that handles log on screen

I have some pesky co-workers who like torturing me via the remote shutdown commands, and because of Group Policy here at work I cannot go to Windows Settings > Security Settings > Local Policies > User Rights Assignments: and administratively remove the "admin" from "force shutdown from a remote system". Changing this has been disabled via GP.

To circumvent this i have tried a manual rename in AD and have hidden deep within an obscure OU to prevent them from finding out my computer name. They CAN however physicall go to my computer and at login go to the username field and type ".\" as you know this will print the computer name below.

The question is, is there a way in the registry to remove that dropdown or at the very least prevent it from displaying text?

Layback Bear said:

You have a computer hooked to a domain/work group maintain by a administrator. You should not change anything with out permission and help from the administrator and/or I.T. Department.
Report the problem you are having with co-workers and let them handle the problem.

I am not quite ready to go that far, though I do appreciate your advice. I am more interested in protecting myself as it has been mostly done in jest so I am not too concerned about that part of it, I am just curous if there is some location in the Registry that I can adjust?

I agree 100% with Layback Bear. The Group Policy is there to prevent the kind of things you are attempting. I am not certain that helping with this is permitted by forum rules.

It really was not my intent to obtain illicit advice and tips. I hope you understand my intention was to PREVENT hacker/pranksters I simply wanted to hide the computer name, I was not aware this broke rule 6. I apologize

What about using a firewall to block the incoming connection that initiates the remote shutdown? If you have local admin rights you can enable Windows firewall (or install a third party one that can't be tampered with GP) to block so they can't send the remote command, even knowing your computer name/ip.
Of course, if they have physical access to your box, you already lost the game.