How can I keep a Windows registry key constant?

Question

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.

NOTES

The key is in:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\MMDevices\Audio\Render\{39de53a5-eb32-44e2-a457-eca85387442b}\Properties

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?

Solution

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.

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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.

Comments

[lyrica]

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 :/

[Scott Chamberlain]

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

[lyrica]

Gotcha. Much obliged!