Windows 11 build 21996

Windows 11 build 21996 is the earliest available build of Windows 11. This build has leaked on 15 June 2021. Some areas already identify itself as Windows 11, however the kernel version remains the same.

System requirements
This build raises the memory requirement to 4 GB of memory. Additionally, on UEFI systems, this build claims to require Secure Boot and Trusted Platform Module support, although it doesn't require either to work. The requirements can be bypassed by installing in legacy mode using the CSM, or by using  to directly apply the install image. It also possible to use this build's  with the installer of Windows 10.

The setup explicitly mentions TPM 2.0 support being required, although it has been found to work with a TPM 1.2 module as well.

New features
This build contains many new and updated features in relation to the user experience. Windows 11 branding has been introduced throughout the operating system. The Out of Box Experience from Windows 10X is used by default in this build, as well as other elements have been updated to be similar with the Windows 10X aesthetic. There is a new sound scheme, which also reintroduces a startup sound.

The Aero visual style has been updated with new neumorphic controls and widgets. The new design makes large use of elements such as rounded corners, shadows, as well as blue accents. This is the first such update since the previous styled controls were introduced during the development of Windows 8. Window frames have also been updated to use rounded corners, although they may still show squared in certain scenarios due to a bug.

The File Explorer icon has been changed in order to be consistent with the new folder icon design introduced previously with Windows 10 build 21343.

The Cloud SKU from Windows 10 has now been renamed to SE.

Start menu and Taskbar
A new taskbar, similar to the one featured in Windows 10X, has been introduced. Unlike previous versions of Windows, the Start button and application buttons are centered by default, rather than aligned to the left, although the old behavior can be reenabled in Settings. The new taskbar also seems to have removed support for custom toolbars such as the Quick Launch panel.

The options to change the location of the taskbar, use smaller icons and show window/applications names in the taskbar have been removed. The setting to show the taskbar on all displays was also removed, although it can be toggled directly using a registry value:

News and Interests have also been removed from the new taskbar and is replaced by Widgets, a panel available from the taskbar that slides from the left and contains weather and news provided by MSN. It is currently unknown if the feature is planned to support third-party content, although the current implementation does not.

Together with the new taskbar, the Start menu has been greatly revamped. Live tiles have been completely removed, with the intended replacement also being the new Widgets panel. The main page shows icons of pinned applications in the top half, with the full list of apps being available by clicking the "All Apps" button in the top right corner. The lower half shows recommended apps and files, which can also be expanded by clicking the "More" button on the right side. The bottom panel contains the power button on the right and the user name and picture on the left, which when clicked reveals links to user account settings, logoff and lock features.

Similarly to the multi-monitor taskbar, the new Start menu can also be disabled using a registry value, reverting back to the Windows 10 design:

Snap layouts
Hovering over the Maximize/Restore button in the window caption by default shows a new menu that allows the user to pick a snap layout, as well as choose the current window's position in it. Furthermore, when multiple windows are snapped next to each other, the taskbar also shows a common window preview for all windows in the layout when hovering the respective apps icons.

Transparent taskbar
When installing graphics drivers on this build, the taskbar will become transparent. It can be fixed by restarting the OS.

Legacy Windows 10 taskbar
When  is started from the SYSTEM account, the old taskbar will be seen.

DWM
Sometimes during the app close animation (as mentioned above) or on certain configurations, the windows will turn to the Windows 10 borders.