BetaWiki:Featured article/2019-02
Windows 8.1 build 9431 is the official Preview build of Windows 8.1, also known as the Milestone Preview. This build was released on 2013-06-26 with the occasion of the Build 2013 conference taking place. At the time of its release, it was possible to upgrade to this build from a Windows 8 copy by using the Windows Store or by downloading an ISO from TechNet or MSDN. The ISOs were made publicly available the day after, on 2013-06-27, when the day 2 keynote started.
An RT version was also released, however, the only way to install this build on such a machine was through the Windows Store. This was also the only way to obtain less common SKUs such as Single Language.