I have a VAIO CW laptop with Windows 7 x64, and after installing new NVIDIA drivers, my screen brightness controls are no longer available. (Not in the control center, not in the power options, buttons don't work even though VAIO's brightness adjust window pops up, etc.).
My display doesn't dim either.
It works fine on other OSes (e.g. Windows 8).
I've tried uninstalling and reinstalling a bunch of drivers (even tried installing the factory-default NVIDIA driver) and software (including the VAIO event service), but it doesn't work.
Any idea how to fix this?