Hi,
Here are some troubleshooting steps that may help.
- First is to uninstall/reinstall the keyboard driver.
- Go to Device Manager and uninstall the Keyboard driver.
- Once uninstalled, reboot the laptop and it should reinstall the driver automatically.
- After the reboot do test if the keyboard will work normally.
- If the same problem will persist, do connect an external USB keyboard and see if it will work normally.
- If using the external USB keyboard will work normally then the problem lies in the built in keyboard.
- Last option to really identify if it's a software or the keyboard itself that is faulty is to reinstall Windows because if after reinstalling Windows will not work you'll need to replace the keyboard itself.
- Before you replace the keyboard, do also try to open the laptop and remove the ribbon cable that connect it to the motherboard then put it back in making sure it's seated properly.
- If it will still not work proceed with replacing the keyboard.