Microsoft today reminded customers that the Windows 8.1 Preview will conk out on Jan.15.
"Now that Windows 8.1 and Windows RT 8.1 have been generally available for a while, it's time to get all your remaining devices that are still running Windows 8.1 Preview or Windows RT 8.1 Preview to the final GA release before the Preview release expires," Microsoft said in a short post to a company blog Wednesday.
"GA," for General Availability, is a label Microsoft uses to denote the final, shipping version of a product.
"You have no right to use the software after this expiration date [of Jan. 15, 2014]," stated the preview's license (download PDF) "Starting from the expiration date, you may not be able to access any unsaved data used with the software."
Microsoft released a single preview of Windows 8.1 on June 25, when CEO Steve Ballmer -- who would announce his retirement two months later -- called on a coffee metaphor to say the update was "a refined blend of our desktop experience and our Modern user experience."
Users who installed the Windows 8.1 preview atop Windows 8 will be able to update to the final version free of charge, but others -- those who tried the beta on a machine that had previously run Windows 7, Windows Vista or Windows XP -- will need to either restore the system's original operating system or pay between $120 and $200 for Windows 8.1.
Neither Windows Vista or XP are designed to be upgraded to Windows 8.1, but users can instead take a circuitous path -- first to Windows 8, from which they can update to 8.1 via the Windows Store -- or follow the steps outlined on this Microsoft support page.
Even those who formerly relied on Windows 8 and experimented with the 8.1 Preview have work to do after an update to the final. "Note that you will have to reinstall all of your applications (desktop or modern) after doing this," Microsoft said today.
According to analytics company Net Applications, Windows 8 and Windows 8.1 accounted for a combined 9.3% of all personal computer operating systems in November, a number that represented 10.2% of all those devices running Windows.
Gregg Keizer covers Microsoft, security issues, Apple, Web browsers and general technology breaking news for Computerworld. Follow Gregg on Twitter at @gkeizer, on Google+ or subscribe to Gregg's RSS feed . His email address is email@example.com.