Laptop screens tend to look duller than desktop screens. Sometimes this is due to a "Matte" finish which gives it a cinema screen look. However, if you have a glossy LCD that looks dull, you may need to tweak some settings to correct this. Whatever the cause, a dark laptop screen makes viewing extremely difficult.
Locate the Fn (Function) key on your keyboard. It may be on the bottom left side with dark blue letters.
Locate the two "brightness" keys near the top of the keyboard. These will be in the "F" keys, possibly if F6 and F7. They should have little sun pictures or something similar to indicate brightness.
Hold down the Fn key while pressing F7, or whichever "F" key your laptop uses to increase brightness.
Tap F7 repeatedly until you reach the desired brightness. Fn must be held down as you continue to tap.
If the Fn in key doesn't work or is not bright enough, you may be able to increase brightness through the video driver. It's usually found in the bottom right corner of the task bar and can be accessed by either double-clicking or right-clicking. The procedure for increasing brightness varies depending on the brand of your video card. Check with your video card manufacturer, most likely Nvidia or ATI, for details on accessing the driver options.