Windows 8 build 7973 (fbl core1 kernel npc)

Windows 8 build 7973 (fbl core1 kernel npc) is a Milestone 3 build of Windows 8. This build updates the boot screen to the fish from the background of Windows 7's pre-release versions with the spinning circles that would make it to the RTM. It was leaked on 2015-09-19 by OSBetaArchive.

Redpill
A version of Redlock was released on 2020-01-29, unlocking all redpill levels on this build, including the start screen.

With this build, the Start screen is beginning its evolution away from the Milestone 2 look of the previous builds. The design for the tiles on this build has changed to a look that more closely resembles the final. The Immersive Control Panel has also been redesigned, along with the splash screen for MS Help being changed to a rather crude one done in Microsoft Paint.

The Metro folder icons and thumbnails seen in build 7963 have been disabled.

Aero
This build appears to have a slightly broken Windows Aero theme, with only the top portion of the window frame using the blur effect, leaving the side borders transparent.