Windows 8.1 build 9478

Windows 8.1 build 9478 is a build of Windows 8.1. It is known that this build exists in the ARM architecture. Five screenshots of it were found on the Chinese website BetaWorld. It was supposedly uploaded to the aforementioned site on 26 October 2019, but at the moment this cannot be confirmed or refuted as it is not publicly available. Russian website PC Portal has also shown a screenshot with the build tag of this build. As of 2024, the build itself remains unleaked.

This build is confirmed by a WinJS 2.0 string which originates from the Windows Store infrastructure.