Hello,To unlock your keyboard all you need to do is---
- Click Start > Control Panel option>
- Double click the Accessibility Options icon (or if you are in the Category View, click the Accessibility Options category, then click on Accessibility Options once more).
- You will see the next window appear.After this in keyboard tab uncheck all the option the OK
If the keyboard is still not responding, try this : https://ccm.net/faq/56867-what-to-do-when-your-keyboard-won-t-type#1