Updating to Windows 8.1 or Windows RT 8.1
Your options for updating to Windows 8.1 depend on how you installed Windows 8.1 Preview or Windows RT 8.1 Preview.
[h=2]I installed the preview from the Windows Store or I installed the preview using media while Windows 8 was running[/h]
You can download the update free of charge from the Windows Store. You'll be able to keep your personal files, but you'll need to reinstall your applications. Make sure you have any original installation media that might be required for applications that were not installed from the Windows Store.
Note
Before updating, make sure you have installed all available updates to your PC. You can do this by running Windows Update and installing all updates. To find out more about using Windows Update, see Windows automatic updating: Frequently asked questions.
To find out more about updating to Windows 8.1, see Updating to Windows 8.1: FAQ.
[h=2]I installed the preview by booting from ISO media[/h]
If you installed Windows 8.1 Preview by booting from ISO media, you can update to the final version of Windows 8.1 Pro using the Windows Store, but your system won't be activated until you buy a Windows 8.1 licence and Product Key. You can do this by following the instructions when you activate your system, or by purchasing a DVD of Windows 8.1 Pro.
If you don't want to buy a copy of the Pro edition of Windows 8.1, you should return your PC to its previous operating system before installing Windows 8.1.