Windows 8 Pro Upgrade Version Cannot Update to Windows 8.1

I bought a legitimate copy of Windows 8 Pro Upgrade version about a month ago. While doing a clean install on my desktop computer, I found out that you cannot do a clean install from an upgrade version of Windows. I figured out how to do a clean install of Windows by following the steps on this website: http://lifehacker.co...an-upgrade-disc

When I open the Windows Store App, I can't find the option that lets me update to Windows 8.1. Is there anyway I can legitimately update my copy of Windows to Windows 8.1?

Take a look at those posts for more info.

http://www.eightforums.com/tutorials/18309-windows-8-windows-8-1-iso-download-create.html

How to download Windows 8.1 ISO with a Windows 8 key.
http://www.eightforums.com/installation-setup/33164-how-download-windows-8-1-iso.html

http://www.eightforums.com/installa...retail-windows-8-1-windows-8-product-key.html

Thanks for the links. I'm currently downloading the Windows 8.1 ISO. Can I do a clean install of windows using the Windows 8.1 ISO and using my original Windows 8 product key?

You can ACTIVATE with Windows 8 Product Key, but not install, use one of the key in the post.

http://www.eightforums.com/installa...retail-windows-8-1-windows-8-product-key.html