Or, if you're in a dark room, you might want to make the screen less bright.Ī brighter display uses more power, which reduces battery life. For example, if you want to use your laptop outdoors on a sunny day, you might need a brighter screen to see the display clearly. If you have a laptop or tablet with a built-in display, you might need to occasionally change the screen brightness level. How to Change Brightness of Built-in Display in Windows 10