The LCD screen on your Compaq Presario laptop may be perfectly visible when you are in a well-lit indoor area, but if you've ever tried using your laptop outdoors or in an area without good lighting you'll notice the screen is much more difficult to view. The Presario line of laptops includes a built-in feature for adjusting the screen brightness. Whether you want your screen brighter or dimmer, you only need to tap a key combination.
Press down the Fn key at the lower left end of your Compaq Presario keyboard. Keep the button held down and tap the F7 key to decrease the screen brightness by one step.
Tap the F7 key again with the Fn key still depressed to further decrease the brightness by one step. Continue hitting the F7 key until you reach the minimum LCD screen brightness.
Hold down the Fn key and tap the F8 key to increase the Presario's LCD screen brightness by one step. Keep pressing the F8 key until you reach the maximum brightness for your screen.