The Pro Gaming Keyboard has keys that let you toggle Game Mode, and enable or disable the keyboard's backlighting:

• Game Mode
• Backlighting

Game Mode
While Game Mode is on, the keyboard disables the Windows and Menu keys to prevent unwanted interruptions. To toggle Game Mode, press the Game Mode key located on the upper right side of the keyboard. The Game Mode LED lights up when the mode is active. 

NOTE: If the indicator does not light up, check your Pro gaming keyboard’s lighting settings. The LED for the Game Mode key might be switched off.

In addition to the Windows, Menu and FN keys, you can disable other keys in Game Mode using Logitech Gaming Software (LGS) 8.91.48 and later. If you don’t have Logitech Gaming Software, you can get the latest version from the LGS download page. Launch LGS, select your Pro gaming keyboard and click the Game Mode Settings icon.

The Game Mode Settings window appears:

Enabled keys are shown in blue, and disabled keys are gray. To re-enable a disabled key, click on the key again. You can disable keys in Game Mode for any individual profile.

NOTE: The Windows, Menu and FN keys cannot be enabled in Game Mode. 

Backlighting
To enable or disable backlighting on your keyboard, press the Backlight toggle key, located above the PAUSE key in the upper right of the keyboard. The LED lights up when backlighting is enabled. 

NOTE: If the backlighting indicator does not light up, check your Pro gaming keyboard’s lighting settings. The LED for the Backlight toggle key might be switched off.