I see....yes, I would recommend AppCenter to prohibit offending applications from executing.

There is no "master" registry key that overrides the operation of the microphone.  That particular subsystem can be disabled, but as soon as an application requests that resource, it will be powered on. What problem is the customer trying to solve?  Perhaps there is another method to fix the problem.

Customer would like to completely disable the microphone since they are in a government facility where the use of microphones is prohibited. They can open the Notes program and that allows user to recoed a voice note with the microphone.... So, George, unless you can provide a different option, i believe Appcenter is the best way to block access to programs that call to the microphone.