Need help disabling auto-brightness

Hello !

First of all, this is the system I'm talking about:
Lenovo Thinkpad T420s
i7-2620m
Nvidia NVS 4200m

I'm not sure if it's some drivers derping or if it's Windows 10, but I get some annoying auto-brightness. If I go on some page that has a dark background, my brightness will go down. If I go on some page that has white background, my brightness will go up.

Basically, if my screen is dark, brightness goes down, and if my screen is light, my brightness goes up. Any ideas on how to disable that ?

Thanks.

Have you tried this: How to Disable Auto Adjust Screen Brightness - ambient light sensor - Ideapad Y560 - Lenovo Support (US)
Seems to be something to do with lenovo power settings.

steve1711 said:

Have you tried this: How to Disable Auto Adjust Screen Brightness - ambient light sensor - Ideapad Y560 - Lenovo Support (US)
Seems to be something to do with lenovo power settings.

Thank you man. Giving me that link, I realized that I don't have 'power manager' installed, but I do have 'power management driver' installed. That was a nice lead. I installed that and now I don't get the automatic screen dimming.
But I still need to tweak the settings, because I get some awkward GPU activity. GPU runs without me running anything on the GPU, and that will affect battery life a lot.

Plus that there was no driver for windows 10 or 8 so I installed the driver for windows 7