from Microsoft’s official site:

Download Windows 11 21H2 ISO File 64-bit from Microsoft Windows 11 version 21H2 (Build 22000) was the initial public release of Microsoft’s current operating system. While Microsoft has since released newer versions like 23H2 and 24H2, many users still seek the original 21H2 ISO for compatibility testing, virtual machines, or specific enterprise deployments. Why Download Windows 11 21H2?

The release of Windows 11 marked a significant shift in the Windows ecosystem, introducing a centered Start menu, rounded corners, and robust security requirements. Among the various versions available, holds a special significance as the General Availability (GA) release—the original "Gold" build that laid the foundation for the operating system.