You may first have to click ▲ in this area. If you don’t see this icon anywhere in the bottom-right side of the screen, open Start and click Control Panel.
If you had to open Control Panel, click Power Options here instead.
If you don’t see the “Screen Brightness” slider at the bottom of the Power Options window, you’ll need to restore it before you can adjust your laptop’s brightness.
You may have to scroll down to find this option.
You may have to scroll down to find this option.
If you still don’t have a brightness slider, your graphics adapter may not support it. You can try to update the drivers for your graphics adapter, or you can try to upgrade to Windows 10.