Hi,
Please do try these troubleshooting steps that may help in solving the issue.
- Do a hard reboot first, remove the battery and AC adapter then press and hold the power button for 20 seconds then boot it back up then test the keyboard.
- Next is to uninstall/reinstall the keyboard driver.
- Go to Device Manager and uninstall the keyboard driver.
- Reboot your laptop once done and it should reinstall the driver automatically.
- After the reboot do test your keyboard again.
- If these doesn't work do connect an external USB keyboard and see if it would work or not.
- If the external keyboard works just fine you can try reinstalling Windows.
- And if reinstalling Windows will not work that's the time you can replace the keyboard itself.