First, try the keyboard on another computer. If it does not work on another PC then the keyboard is defective.
Second (if the keyboard works), with the keyboard connected to your PC, enter the BIOS settings and see if it works in the BIOS.
If it works on another computer, and in your BIOS, but not in Windows then:
- Shut off the computer.
- Remove the keyboard
- Start up > go into Windows
- Open the Device Manager > Find the keyboard entry > Right click on the keyboard > Uninstall the keyboard
- Restart the computer
- Once you are on the desktop, plug the keyboard in and let Windows discover it and re-load the driver.
Let us know what you find.