Laptop screens tend to look duller than desktop screens. Sometimes this is due to a "Matte" finish which gives it a movie theater 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.