Hi,
Here are some troubleshooting steps that may help you identify the issue but it seems like a hardware problem to me.
- Check keyboard language settings.
- Open Control Panel and look for Region and Language.
- Check all tabs if they are all set to United States.
- If that doesn't work, 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.