On - The keyboard backlight stays on - until you press Fn + Z to turn it off.It will stay on as you type, until you stop typing for the number of seconds specified in the Backlight Lighting Time field, which you can increase or decrease to suit your preference. Auto - The keyboard backlight will turn on when a key is pressed.The Illumination properties page will appear, as shown below.

In the HWSetup app, click the Illumination tab. You can change the settings for the keyboard backlight in Toshiba Hardware Setup: Click the Windows Start button, then click All Programs, Toshiba, Utilities, and HWSetup. Press this same Fn + Z hotkey combination to turn it off again. To turn it on, press and hold the Fn key, and then tap the Z key. The backlight that illuminates the keys on the computer's keyboard is off by default.