Windows: How to change monitor's backlight brightness

Question

Ever since I've been using an external monitor with my laptop, when I need to change the backlight brightness I have to press the monitor's buttons to navigate through its menu and adjust the brightness.
That is really a pain. It's too many button presses! When I was using my laptop's integrated monitor, that was as simple as presing the Fn key plus a combination.

Probably some of you might think it is not possible to change that programmatically. I thought that too. But I've just found a control (a GUI control) in my video card configuration that does exactly that.
So, that proves it is possible to change this programmatically.

But I can't find any tool or utility that does that. All what I've found are tools that adjust gamma, brightness and contrast. But backlight brightness is a different thing.

Does any of you know how to adjust that damn thing programmatically in Windows?

Answer 1

Let's try that again. There is a SetMonitorBrightness function, but it is only available starting with Vista. There is also IOCTL_VIDEO_SET_DISPLAY_BRIGHTNESS which is available starting with XP SP1. I might give that a try on my laptop just out of curiosity.

Answer 2

I know this question is about Windows, but if anyone is looking for the Linux way to do this you can run the "xbacklight" program, for example: "xbacklight -set 100" to set to 100% (full) brightness. The source code to this program could be used to embed it into a program.

Answer 3

If you have an NVidia card with the control panel installed, you should have a brightness control on the Adjust desktop color settings node.