Windows 11, version 21H2

The original version of Windows 11 (also retroactively named version 21H2 and codenamed "Sun Valley") was released in October 2021. It carries the build number 10.0.22000. It was retroactively named "version 21H2" by Microsoft per its naming conventions that are labeled "YYHX", with YY representing the two-digit year and X representing the half-year of planned release (for example, version 21H2 refers to builds which initially released in the second half of 2021).

Overview
The first public preview build was made available to Windows Insiders who opted in to the Dev Channel on June 28, 2021. Notable changes in this version include:
 * Redesigned Fluent Design System:
 * Most interfaces in Windows 11 feature rounded geometry, refreshed iconography, new typography, and a refreshed colour palette.
 * Windows 11 also introduces "Mica", a new opaque Material that is tinted with the color of the desktop wallpaper.
 * Significantly redesigned Start menu, adhering to the principles of the updated Fluent Design System.
 * Center-aligned Taskbar, with new animations for pinning, rearranging, minimizing, and switching apps.
 * The File Explorer has been refreshed with the Fluent Design System and the Ribbon interface has been replaced with a new command bar with a revamped user interface and a Mica background. It also introduces revamped context menus with rounded corners, larger text, and Acrylic.
 * New Windows Subsystem for Android.

The update has reached end of service on October 10, 2023 for Home, Pro, Pro Education and Pro for Workstations editions. The Enterprise, Enterprise multi-session, IoT Enterprise and Education editions will reach end of service on October 8, 2024.