Laptop brightness not adjustable?

Question

Windows

Hello, I'm asking for help.
Today, sitting down at a laptop (new, lenovo z5070, win 8.1), I noticed that the brightness is not adjustable. In the computer settings and by pressing the keys, the brightness does not change. None. Already googled, asked friends - no one faced this problem. I did not install Windows updates, only 1 program yesterday. How to solve this problem?

Answer 1

Look only towards the drivers. It's on the video. Because of them, even the backlight of the screen disappears. Completely remove the driver and install it after downloading it from the manufacturer's website. Pay attention to the OS version and its bit depth (32 or 64).
Also, the backlight may not change due to the driver for hot keys that work through the 'Fn' key. In most cases, it comes as not a driver, but a utility. Well, just in case, check the driver for the chipset