Windows 10 build 18946

Windows 10 build 18946 is an internal build of Windows 10 May 2020 Update. This build was not intended to be released but it was accidentally flighted to all insiders in the Fast Ring on 24 July 2019. It is currently the only available build of the  branch.

Breaking the known insider releases routine, Microsoft managed to also release the rs_prerelease and rs_xbox compiles of build 18947 before pulling all three releases after publishing the AMD64 variant of this build within five minutes.

They also broke the UX routine and showed up with some new major changes.

New features

 * Fully redesigned Start menu. It was intended to be used in the Windows 10X operating system. It works properly only with the Light theme.
 * New Control Center and Notification Center design. Now it's more compact and convenient. By default it only shows buttons, but it expands as you receive notifications.

Enabling the new features

 * To enable the new Start menu, download mach2, then run an elevated command prompt session and type in.


 * To enable the new Control Center and Notification Center design, open Registry Editor and then navigate to . Once there, create a DWORD value named UseLiteLayout. After you create it, set its value to 1.