

You should now be able to increase or decrease display brightness.

I think that it can have a connection with the fact, the T450s officially only compatible with B140HAN01.3 (and mine is now 1.2).

I think it just some driver issue, because as you see the laptop is compatible with the screen. It works in BIOS, work without driver (it doesn't overwrite the BIOS settings), but when i install the driver this feature disappear from windows and set it to maximum brightness automatically. When I install intel HD Graphics driver, the brightness control doesn't work anymore. This is the id of the screen: B140HAN01.2 I've updated my old HD+ AUO TN sreen to an FullHD AUO IPS screen.
