1
Open Command Prompt, then paste in this command and press Enter:
msdt.exe -id KeyboardDiagnostic
Run that Keyboard Troubleshooter to see if that can solve the problem.
2
If that does not resolve this for you
Open Device Manager
Expand the Keyboards section
Right click your keyboard and choose 'Uninstall'
Then restart your PC and check if the keyboard is functioning correctly.