Windows 8 build 8133 (fbl grfx dev1)

Windows 8 build 8133 (fbl_grfx_dev1) is a build of Windows 8, which was leaked on 31 December 2019.

It is the first build in which the spinning circle replaces the progress bar when installing Windows when booted into Windows.

Hardware compatibility
It is recommended to set the hardware compatibility to version 9.x on VMware, otherwise booting from setup will result in a garbled black screen.

Segoe UI
As of 2021, it is the earliest leaked build to use the new version of the Segoe UI font that would be used in later builds through to the final version.