Press the keyboard backlight hotkey, usually Fn + F7, on many ASUS laptops
Try Fn + F3 or Fn + F4 if your model uses different brightness controls
Look for a key with a keyboard light icon and press it with Fn
Press the backlight key repeatedly to cycle through brightness levels
Check ASUS Armoury Crate or MyASUS for keyboard lighting settings if available
Use the keyboard backlight shortcut in Windows Mobility Center if your model supports it
Make sure your ASUS laptop model actually includes a backlit keyboard
Update ASUS keyboard or hotkey drivers if the shortcut does not work