Windows 10 build 9807

Windows 10 build 9807 is a pre-Technical Preview build of Windows 10 originally released to Microsoft partners participating in the Ecosystem Engineering Access Program (EEAP), as indicated by the  branch. The x86 compile of this build in Simplified Chinese was uploaded on 17 May 2022. It is the last known build to refer to itself as its predecessor.

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.

User interface
The user interface has undergone many significant changes since build 9785. The Windows Aero theme has been updated to feature thin borders (although its Lite counterpart remains unchanged). Native windowing support for Metro applications is now enabled by default, complete with a new window border skin that distinguishes Metro apps from regular Win32 applications. A new flat icon set that is reminiscent of the ones found in later Windows 10 builds has also been introduced, replacing a number of icons first added with the releases of Windows Vista and Windows 7.

Task View
The Task View, a function that allows the user to either have more than one desktop at a time or switch to different applications in a similar manner to the Task Switcher (Alt menu), has been implemented, and can be invoked by clicking on its taskbar icon or by pressing the Win hotkey. The Task Switcher has also received a design uplift to look more similar to the newly implemented Task View feature.

Notification Center
The Notification Center can now also be opened starting with this build; however, a majority of its functionality is not implemented and will therefore only detect incoming notifications via its respective taskbar icon.

File Explorer
The File Explorer application has also been updated to feature thicker metrics in the navigation menu along with a new Share button located within the ribbon.

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.

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

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

Taskbar preview border color
If window auto-colorization is enabled, the taskbar preview borders 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 by restarting Windows.

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