The free ride is coming to an end
If you've been sitting pretty with a Windows 8.1 Preview license and have intentions of sticking with it for any length of time, you may want to add a retail copy to your holiday wish list and start dropping hints for your friends and family. Microsoft posted a reminder on its TechNet blog giving users a heads up that the Windows 8.1 Preview license will expire sometime in January 2014, though the Redmond software giant didn't specify an exact date.
"Plans should be made to move to the released version of Windows 8.1 or return to the prior OS version as soon as possible to avoid interruption in use of the device on which the Windows 8.1 Preview was installed," Microsoft stated .
How you update from Windows 8.1 Preview to Windows 8.1 (or Windows RT 8.1) will depend on how the Preview version was installed. You can reference a special webpage Microsoft setup with detailed instructions on how to make the transition. To summarize, if you installed the Preview from the Windows Store or installed the Preview using media while Windows 8 was running, you can download the update from the Windows Store.
If you installed the Preview by booting from ISO media, you can updated to the final version of Windows 8.1 Pro using the Windows Store, but your system won't activate until you buy a license and product key.