Press Num Lock or Fn + Num Lock
Check if the keyboard has a dedicated keypad lock key
Restart the laptop
Turn off Filter Keys in Accessibility settings
Update or reinstall the keyboard driver
Check BIOS/UEFI settings for keyboard options
Connect an external keyboard to test input
Clean the keyboard if keys are physically stuck
Run the built-in keyboard troubleshooter
Contact the laptop manufacturer if the keypad still does not work