Press and hold the "Fn " key in the lower left corner of the Gateway's
keyboard. It is the first key on the left.
Press the up arrow key in the lower right corner of the keyboard to
increase screen brightness. The key is printed with a sunburst icon.
Holding the key will increase brightness to the maximum setting.
Pressing and releasing the key will increase brightness in smaller
increments.
Press the down arrow key in the lower right corner of the keyboard
to dim the screen. The key is printed with a sunburst silhouette.
See: http://www.ehow.com/how_6776262_change-brightness-gateway-laptop.html
Microsoft® Security MVP, 2004 - 2010