How to reinstall Windows 8?



I first bought and upgraded my Windows 7 laptop to Windows 8 after release. Is there any way I can wipe my computer and re-install Windows 8?
When I go through the Windows 8 setup again my Product key that I purchased the first time no longer works.

Thank You


If it’s the Windows 8 ‘upgrade’ version. You will need to first install Windows 7, then upgrade to Windows 8.