Since installing Windows 10 or Windows 8, have you noticed that your laptop screen is very dark? Even though you've set the brightness level, it may still be dark. A new feature in Windows 8, adaptive brightness, will control the brightness level of your screen. You can disable this in the power options advanced settings.
- Go to Control Panel > Hardware and Sound > Power Options, then click on "Change plan settings" next to your active power plan.
- Click on "Change advanced power settings."
- Scroll down to Display, then under Enable adaptive brightness, switch it off for both the battery and plugged in modes.