How to Activate Windows 8.1

I bought parallels and downloaded and installed Windows 8.1 preview via the parallels installer.

I'd like to buy Windows now. When I go to Control Panel > System & Security > System in Windows it says Windows is Activated but I installed the preview.

How can I activate Windows? Does this preview last forever or will it expire?

Thank you

 

http://windows.microsoft.com/en-us/windows-8/update-from-preview

 

Thanks Brockly

The windows store "card" in metro never connected, but putting ms-windows-store:WindowsUpgrade in the address bar did succeed in opening the store.

I appreciate the help.