How do I prevent a registry entry from being changed?

After many years, I stumbled across way to keep Windows from sleeping my soundcard. The problem being that Windows seems to think the sound needs to be shutdown after every freaking second of no use and the my laptop speakers pop loudly when the audio wakes up (This used to be a non-issue ages ago, but Realtek/Acer/Microsoft - in their infinite wisdom, decided to remove the power management option from the control panel).

Anyways, this is the post I found: https://www.tenforums.com/sound-audio/12589-windows-10-popping-sound-speakers-4.html#post1751331.
Works a charm except for some reason (shutdown, reboot, power change, I haven't isolated it) that registry entry will reset and I need to change it all over again.
Is there a way to lock it down so it won't auto-change? I did find a post saying that adding "everyone" to the permissions and denying all would work, but the post was years old and I don't know if it's still relevant or even would work.

Cheers.

 

By making the Owner/Admin account password protected and creating a Limited User account to use. That's how you protect it. If you use the Owner account that is the same as Admin account and anything you or malware does is consider Admin changes and will permit the changes. So create a limited user account and use that to prevent unauthorized changes and use Owner/Admin for update only. As that is a laptop then you should contact the hardware manufacture as that seems to be hardware related issue as well.
But first what needs done:
1. Create Owner/Adming account password protected
2. Create Limited User account for everyday usage to protect your system O/S.