Every version of Windows has a unique product key, which is different from the same versions run on other systems throughout the world. In case you want to know your windows 8 product key, here is the list of steps you can follow:
1. Click on Windows Explorer Icon and right clilck on Computer from the left task pane. Click Properties.
2. A new window would pop-up for System properties where you would scroll down to find the Product ID: of your Windows 8. This is your Product Key.