Checking the running services on my Windows 7 system, I came across a service named "Adaptive Brightness".
The description: "Monitors ambient light sensors to detect changes in ambient light and adjust the display brightness. If this service is stopped or disabled, the display brightness will not adapt to lighting conditions."
That sounds cool - but my monitor and my system doesn't have this sensor.
According to
http://windows.microsoft.com/en-US/windows7/Adjust-your-monitors-brightness-and-contrast:
"Adaptive brightness is a feature in
Windows that uses a light sensor to automatically adjust the display brightness to match the lighting conditions in your computer's surroundings. To use adaptive brightness, you must have light sensors installed and enabled on your computer."
So just another shiny thingy on the big Christmas tree called windows.
And yeah, I disabled it.