Is there a way to lock a system registry key from being changed? Or to somehow keep it constant?

In Windows 7, I'm trying to prevent a system registry key from being automatically changed any time a monitor is turned off or my system is rebooted.


The key is in:


It's where Windows sets the properties for a particular sound device (my HDMI sound output). Anytime a monitor is turned off or system rebooted, Windows resets the speaker configuration of this device to a 2-channel "Stereo" setup, and resets the sampling rate/bit depth to 16bit/44KHz.

I'd like to lock the respective keys/properties to prevent Windows from constantly resetting them.

Without any pre-clearance from those knowledgable, I'm hesitant to tamper with permissions of a system-level key like this. If this is an impossibility to lock a system-level key such as this, is there a way I can somehow script/program a way to poll this registry key, and if changed, set it back to the settings I want?

Any ideas?

1 Answer 1


You can set permissions for registry keys. Just remove Edit permissions from SYSTEM and the Administrators group and the key should be effectively read only.

However if that does not work you can just use the reg command in a start-up script and have it reset your key every time you unlock your computer.

  • Thanks! So am I not playing with "fire" by locking a system registry key such as this? I fear that I'd incur the godly wrath of the Windows kernel by doing so :/ Apr 19, 2013 at 0:23
  • Honestly, I don't know. Doing this could do anything from resetting the security settings and doing nothing at all to giving you a BSOD the first time it tries to reset it. Make sure you backup your system before you try anything Apr 19, 2013 at 2:55
  • Gotcha. Much obliged! Apr 20, 2013 at 6:53

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