My laptop (HP ENVY) isn't actually changing its brightness when I switch brightness.

Basically the title says it all, my computer is stuck on max brightness so the battery is suffering and using my laptop at night is now a pain. I already updated the display adapter and the option to change the brightness in my display settings is there but moving around the slider doesn't actually do anything.

from Windows Central Forums http://ift.tt/29mvAUN
via IFTTT