UPDATED: Windows 8.1 Hits Release-to-Manufacturing Stage

Windows 8.1, the update to Microsoft's Windows 8 operating system, has been released to manufacturers, according to reports from sources.

UPDATE, 8/27: Microsoft confirmed Windows 8.1 and Windows 8.1 RT have hit RTM in a blog post Tuesday.

Windows 8.1 is scheduled to become generally available in October. Microsoft has not confirmed whether Windows 8.1 has reached RTM, but Windows SuperSite's Paul Thurrott Tweeted on Friday that the final build number is 9600.16384.130821-1623.

The date fits Microsoft's previously discussed timeline. Tami Reller, corporate vice president and chief marketing officer for Windows, said during July's Worldwide Partner Conference that the final Windows 8.1 build would be available to manufacturers by the end of August.

Redmond magazine columnist and Microsoft watcher Mary Jo Foley wrote in a blog post that multiple inside sources have confirmed to her that Windows 8.1 has reached RTM status.

"I talked to another contact of mine who said the internal RTM e-mail made the rounds inside the Windows division on August 23," wrote Foley. "A third source close to the company confirmed Microsoft RTM'd Windows 8.1 on August 23, and announced internally that the quality metrics for Windows 8.1 were back in line with those of Windows 7."

When contacted directly by Foley, Microsoft said it had no comment.

Foley speculated that the reason why an official announcement wasn't made on Friday was so that it wouldn't overshadow the announcement of CEO Steve Ballmer's retirement.

With the RTM status of Windows 8.1, PC and other hardware makers can start preloading new Windows 8 machines with the update for product launches on Oct. 18 -- one day after current Windows 8 users will be given access to the upgrade via a free download.

Previously, when a Microsoft product hits the RTM status, the ability for IT pros to test the final build through the TechNet program would occur shortly after. However, due to Microsoft ending the TechNet program on Aug. 1, there has been no word on whether testing of the final build would be available.

In the meantime, Windows 8 users have had access to the Windows 8.1 Preview since late June through the Windows Store.

Microsoft has not indicated whether Windows Server 2012 R2 and System Center 2012 R2, both scheduled for release on Oct. 18, have also reached the RTM milestone.

About the Author

Chris Paoli (@ChrisPaoli5) is the associate editor for Converge360.