Windows 10 build 9807

Windows 10 build 9807 is a pre-Technical Preview build of Windows 10, which was uploaded to the BetaWiki Discord server on 17 May 2022 only in the Simplified Chinese language and under the x86 architecture. This build was originally released to Microsoft partners participating in the Ecosystem Engineering Access Program (EEAP), as indicated by the  branch.

It is the first build to update the kernel version to 6.4, and the last build to refer to itself as Windows 8.1.

The copyright year in winver was updated from 2013 to 2014. This persisted up to build 9883.

A PDF file detailing release notes as a part of the EEAP release of this build was posted several minutes after the build itself, identifying two previous EEAP releases. The SDK for this build identifies as the "Windows Software Development Kit for Windows 8.2" per this document.

Aero changes
The Aero theme's window borders have been made thinner, though the Aero Lite theme still has the thicker border style.

Windowed Metro
Native support for windowed Metro apps is now enabled by default. The title bar of them also received its own style.

New icons
Some icons (including Explorer's) have been changed to a flatter style.

Notification Center
An early version of the Notification Center.

Task View
A multi-desktop mode has been introduced.

Metro UI
Dragging a window in full-screen mode in Metro apps will result in Metro UI transitions from Windows 8.1.

Explorer.exe error during shutdown
When the system shuts down, a memory access error related to  may occur.

Timebomb
Like other Windows 10 builds found in the  branch, this build contains a non-functional timebomb and as a result can be installed on the current date.

Search icon on the taskbar
If the task view is enabled, the search icon on the taskbar will not be displayed correctly.

Window thumbnail border color error
If window auto-colorization is enabled, the window thumbnail borders on the taskbar do not change color even after the wallpaper changes. This issue can be remedied by manually changing the window color through the Control Panel or restarting Windows.