with some laptops, look for extra symbols on a couple of the keys (usually the number keys) which look like a sun. They usually increase and decrease brightness, but you have to hold the function (Fn) key as well.
Also note that with most laptops the screen will be dimmer when running on battery power, to preserve battery life.
Windows 7 x64 Ultimate Edition, Gigabyte Z77-D3H, Ivy Bridge i7 3770, nVidia GTX480 1.5Gb, 16Gb Corsair 1600MHz, Creative X-Fi, Seagate 500Gb SATA II, DGM 23" Widescreen TFT
"Men never do evil so completely and cheerfully as when they do it from religious conviction" -Blaise Pascal