Windows 8.1 , the first major update to Windows 8 and RT, was officially announced by Microsoft on May 14, 2013. Following a presentation devoted to the update at Build Conference 2013, a public beta version of the update was released on June 26, 2013.Windows 8.1 was released to OEM hardware partners on August 27, 2013, and released publicly as a free download through Windows Store on October 17, 2013. Volume license customers and subscribers to MSDN Plus and TechNet Plus were initially unable to obtain the RTM version upon its release; a spokesperson stated that the change in policy was to allow Microsoft to work with OEMs “to ensure a quality experience at general availability.” However, after criticism, Microsoft reversed its decision and released the RTM build on MSDN and TechNet on September 9, 2013.
Microsoft markets Windows 8.1 as an “update” for Windows 8, avoiding the term “upgrade.”Microsoft’s support lifecycle policy treats Windows 8.1 similar to previous service packs of Windows: It is part of Windows 8’s support lifecycle, and upgrading to 8.1 is required to maintain access to support and Windows updates after January 12, 2016.
Retail and OEM copies of Windows 8, Windows 8 Pro, and Windows RT can be upgraded through Windows Store free of charge. However, volume license customers, TechNet or MSDN subscribers and users of Windows 8 Enterprise must acquire standalone installation media for 8.1 and install through the traditional Windows setup process, either as an in-place upgrade or clean install. This requires an 8.1-specific product key.
Upgrading through Windows Store requires each machine to download an upgrade package as big as 2–3.6 GB. Unlike the traditional Windows service packs, the standalone installer, which could be downloaded once and installed as many times as needed, requires an 8.1-specific product key.
New retail installation media of Windows 8.1 were released alongside the online upgrade. Unlike their Windows 8 counterparts, they can install Windows on computers that do not have an operating system at all. Microsoft stated that the change was in response to customer feedback, and to allow more flexibility for users. Pricing for the retail copies of 8.1 remained the same.
On July 1, 2014, acknowledging difficulties users may have had through the Windows Store update method, Microsoft introduced a “pilot program” that would allow Windows 8 and RT 8 to be automatically updated to 8.1 through Windows Update.
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