First start with the driver, it is the easiest solution. Open Device Manager, if you're using windows, click Start, right click on My Computer, and select Properties. Now click the Hardware tab, then the Device Manager button. Or you can search by clicking Start, then type Device Manager, and press ENTER. Next find your keyboard name under Keyboards. Right click it and select Uninstall. When it is uninstalled, click Action, then click Scan for hardware changes. This will re-install the driver and may help fix the problem. If it doesn't work, you then need to try to figure out if it is a hardware problem. If it's hardware, first plug in an external keyboard via USB, and try using that. If the problem isn't fixed, then the keyboard is not the problem. Since it is a hardware problem, the best way to guarantee a solution is to completely replace the keyboard. However, you may want to seek a professional to do that for you. Any market that sells laptops or PC products are great resources to go to!

Check the power supply and make sure that the battery has charge. If you're not sure how to do this, remove the battery and use the main charger that came with your laptop. Also make sure the charger has the correct voltage and current for your laptop. Typically a laptop voltage requires 16-20V.