Acer Gateway Brightness problem solved

I encountered a problem with Gateway laptop. The brightness level can't be changed neither from keyboard shortcut nor from gnome-power-manager.

If you encounter the same problem, open terminal and type

xrandr --output LVDS --set BACKLIGHT_CONTROL native

or

xrandr --output LVDS --set BACKLIGHT_CONTROL legacy

To make this fix permanent add the above line in your startup(From Menu, System, Preferences, Startup Applications).