I suggest you test the driver.
If you are using windows.
Left click on my computer / properties / on the left tab click on Device Manager / Keyboard
Check if the driver is showing up on the manager.
If it is a problem in the hardware and not in the driver ... If you have a little knowledge, you could try to unplug the keyboard and plug it in again to see if it will solve.
I advise you to take a technical assistance if you do not understand anything about computers. I say this because if suffer any damage at the time of unplugging the keyboard or dismantling the notebook, it may be irreversible.