You should have 3 options. Use the laptops attached keyboard, use the onscreen keyboard, or attach an external keyboard.
If the attached keyboard is giving you problems you can try...
1. Uninstall the keyboard driver.
2. Reboot the computer (without reinstalling the driver).
3. When it restarts, it should reinstall the driver on its own.
If this doesn't work, you may wish to try connecting/reconnecting an external keyboard and see if it works fine. If it does, then it could be the keys themselves that are the issue. You may then need to replace the attached keyboard.