Windows 10 build 21390.1

Windows 10 build 21390.1 is the twentieth Insider Preview build of Cobalt, and is the last known build of Windows 10 (excluding CUs) before the announcement of Windows 11. This build was released on 26 May 2021 to all Windows Insiders on the Dev Channel.

Changes

 * Task Manager and Windows Installer packages now have updated icons.
 * The Mail and Microsoft Store apps are no longer pinned on the taskbar by default on clean installations.

News and interests

 * The flyout might occasionally flash in the screen's top left corner when opened.

Camera Settings

 * The Camera app does not respect the brightness adjustments made to a camera under its respective page.

OOBE

 * The OOBE may use an incorrect font when this build is ran under Simplified Chinese language pack.

General

 * The update process to this build has a chance of hanging for extended periods of time.
 * Search results in the taskbar flyout are not displaying correctly in the dark theme.
 * The icons for Microsoft Edge and File Explorer in the taskbar are swapped in clean installations. This has been fixed in Windows 11
 * In some cases, audio and video devices that are installed on the system may not work despite showing up in device manager. The chances of the user encountering this bug increases the longer they use this build.

Upgrade

 * There is a chance that the default app mode color will be reverted back to Light from Dark.
 * Sometimes the build may use an incorrect font in several languages.