Windows 11 build 21996

Windows 11 build 21996 is the earliest available build of Windows 11, which was leaked on 15 June 2021. Some areas already identify itself as Windows 11, although many areas still report Windows 10, such as the boot menu, the clean installer, and rolling back to an older Windows version.

System requirements
This build raises the memory requirement to 4 GB of memory and a dual core processor or more. 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.

Alternatively, this build's  can be used with the installer of a Windows 10 build, however, it removes the ability to upgrade. Replacing  on the install media with a version from Windows 10 has also been found to work, which preserves the upgrade capability.

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. Window frames have also been updated to use rounded corners, although they show squared when a graphics driver is not present and DWM is forced to use software rendering.

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.

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 ability to open the context menu for applications on the taskbar by dragging up on the icon is no longer present.

The options to change the location of the taskbar 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:

Similarly, the option to use smaller icons in the taskbar has been removed from the Settings. However, this is likely a temporary change as a new registry setting has been introduced that adds a new, larger than default mode for the taskbar:

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.

SE edition
This build renames the Cloud Edition SKU previously introduced in build 21354 to "Windows 11 SE". The edition appears to be targeted at enterprise customers, as it removes customer oriented features such as Your Phone and Widgets and disables the Microsoft Store. It is also required to log in using a Microsoft account during the OOBE. However, unlike Windows 10 S, there is no limitation regarding running Win32 apps not downloaded from the Store.

Touch Improvements
The build also introduces many changes regarding support for touch devices. The tablet mode has been scrapped completely. The advanced multi-touch gestures previously supported only on touchpads can now be used with a touch screen as well. Smaller improvements to simplify the experience of the Windows desktop for tablet users have also been done, such as the hitbox to move and resize windows having been enlarged, as a result windows are now far easier to manage. In addition, while being moved, windows are encased in an acrylic border.

General

 * When  is started from the SYSTEM account, the old Windows 10 taskbar will appear instead of the new one.
 * When updating folder options, the File Explorer window might flicker in the background.
 * The Widgets pane's contents may fail to render on certain devices, the user can still interact with them.
 * Sometimes the Search Box shows a black box instead of the search reslults.

Out of Box Experience

 * When installing N editions, OOBE will fail to load and will lead to a blank screen.
 * The "Forgot your password?" link when setting up a Microsoft account or unchecking the option to receive promotional emails lead to a blank screen.

Desktop Window Manager

 * The taskbar may become fully transparent on some configurations when installing graphics drivers.
 * Window frames appear squared with software rendering or during the close animation.
 * Pressing and holding on the Close button on some UWP applications (like Settings app) revealed a small white corner on the close button.
 * There are multiple glitches with application windows that use the DWM to expand the former glass frame into their client area, such as the Windows Mobility Center.
 * When not maximized, only a shadow or window frame is shown, although the taskbar thumbnails are rendered correctly.
 * When maximized, the window contents are shown correctly, however, the background is fully transparent (with some exception on some programs that use blur effect like CustomizerGod, which keep the blur effect instead of being fully transparent).
 * Dropdown menus may fall back to square corners in some applications after being shown once with rounded ones.
 * The animation that occurs when viewing two taskbar thumbnails next to each other does not render.