To adjust brightness automatically
Some PCs adjust screen brightness automatically based on how much light there is in the room where you're using the PC. To see if your PC has this setting, follow these steps.
1. Swipe in from the right edge of the screen, tap Settings, and then tap Change PC settings.
(If you're using a mouse, point to the lower-right corner of the screen, move the mouse pointer up, click Settings, and then click Change PC settings.)
2.Tap or click PC and devices, then tap or click Display.
3. Make sure the Adjust my screen brightness automatically slider is turned on.
(If you don't want the screen brightness to change automatically, tap or click the Adjust my screen brightness automatically slider to turn it off.)
4.Tap or click Apply.