T440s, Win8.1, dynamic/adaptive brightness

[northyen.dk]

There is a multitude of guides out on the web that describes how to disable the brightness being dynamic. It's currently a huge nuisance, and I simply can't get rid of it, when plugged in.

So I've tried the following:

1. Disable the Windows service "Sensor Monitoring Service"
2. Disable Adaptive Brightness in Windows power options
3. Disable any kind of feature related to the problem in Intel graphics power settings. However the setting I want to adjust does not exists on plugged in power.

Any ideas on what it could be, that apparently forces me to live in misery?