architecture, marking the end of an era for older hardware compatibility in the primary development pipeline. Key Features and Testing

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Further changes to icons and folders within File Explorer improve consistency with the overall refreshed design. 2. Windows Terminal as Default

For developers, Build 21390 allowed you to set (version 1.9+) as the default command line application. This replaced the aging legacy Console Host for PowerShell, CMD, and WSL.

: This build featured an early preview of the new system font and desktop icons that defined the Windows 11 aesthetic.

represents one of the most unique and historically significant milestones in the history of the Windows operating system . Released to the Dev Channel on May 26, 2021 , under the "Cobalt" development branch , Build 21390 was the final major preview build to carry the "Windows 10" moniker before Microsoft officially unveiled Windows 11.