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What controls the brightness levels in a laptop? Is it the BIOS?

Is it possible to modify the brightness levels to have a custom brightness at each level?

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up vote 4 down vote accepted

From Brightness Controls on Integrated Display Panels:

In Windows operating systems, brightness controls are implemented in the operating system-supplied monitor driver, Monitor.sys. The monitor driver implements a Windows Management Instrumentation (WMI) interface to let applications—such as the operating system’s brightness slider—interact with the brightness level.

The monitor driver registers with the operating system device power policy so that brightness levels respond to changes in power policy. The monitor driver registers for Advanced Configuration and Power Interface (ACPI) notifications to process ACPI-based brightness shortcut keys.

An OEM can implement brightness control by using function shortcut keys such as Fn-F6 or Fn-F7.

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+1 Thanks Mehper, this is useful. Do you have any idea where to start modifying a monitor driver? – aCuria Oct 26 '10 at 7:13
You're welcome. Sorry but I have no experience in that. Maybe you can ask another question on how to modify a monitor driver? – Mehper C. Palavuzlar Oct 26 '10 at 7:22

most laptops will have settings for brightness up and down that you can access with a function key (usually labeled as fn) in conjunction with some of the F keys (for example the F7 (down), and F8 (up) keys on my laptop or any HP for that matter).

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Hi MaQleod, those are the settings I want to modify. I want the brightness settings to be linear, and i want to know how to change the brighness at each level. – aCuria Oct 26 '10 at 7:12

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