Hi,
Here are some troubleshooting steps that may help.
- Do a hard reset first, remove the battery and AC adapter then press and hold the power button for 20 seconds then see if the laptop will be back to normal.
- If that doesn't work do try these other troubleshooting steps for your keyboard.
- Try pressing those following keys which are not working using your onscreen keyboard (Ease of Access look for Onscreen keyboard)
- Connect an external keyboard and see if the same problem will persist because if does you may need to consider on doing a complete Factory Reset cause it's a problem with your operating system.
- If all these will not work I would suggest replacing the keyboard itself.