Brightness control on external monitors has never been supported in Windows though, partially due to issues with displays that have poor write endurance on internal storage.

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tylerflick 3 days ago | parent | next [-]

Monitor brightness is controlled over CEC which is just i2c. Windows most certainly supports this on an OS level.

	▲	fainpul 2 days ago \| parent [-]
		Yes, I've used this in the past: https://learn.microsoft.com/en-us/windows/win32/api/highleve...

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user_7832 2 days ago | parent | prev | next [-]

It might not be an "internal windows" tool, but I have controlled an ancient monitor (I think over VGA?) using a 3rd part app on windows. The buttons had broken, but software control worked just fine.

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poolnoodle 3 days ago | parent | prev [-]

I change brightness all the time with a little tool called Monitorian.