Windows 8.1 build 9299

Windows 8.1 build 9299 is a Milestone 1 build of Windows 8.1. A 64-bit checked/debug version leaked on 2019-03-30 on BetaArchive. Due to its earliness, it still identifies itself as Windows 8 in many places and the kernel version is still 6.2.

Timebomb
Like most Windows 8 builds, this build has a semi-broken timebomb, which gets nulled if you install on current date. If you do that, you won't be able to change the wallpaper, unless you use a tool like DeskImg. This also causes some less significant bugs, such as the build booting up to a blank screen after logging in, instead of loading the start screen directly.