Turn on the laptop and wait for Windows to load
Press the keyboard backlight key (often marked with a light icon)
If needed, press Fn + the backlight key
Press the backlight key again (or Fn + backlight key) to cycle brightness levels or turn it off
If there is no dedicated backlight key, check for an F-key with the light icon and use Fn + that key
Open Dell Command | Power Manager (if installed) and enable keyboard backlight (if available)
Check Windows Settings: Settings > Personalization > Keyboard (or Backlight/Lighting if shown) and turn it on
If the option is missing, install/update Dell drivers from the Dell Support site for your exact Inspiron 15 3000 model
Restart the laptop after driver updates