Windows 10 build 9821

Windows 10 build 9821 is a build of Windows 10, which was originally released to Microsoft partners participating in the Ecosystem Engineering Access Program (EEAP), as indicated by the fbl_partner_eeap branch. Polish website WinClub.pl published a screenshot of this build on 18 September 2014.WinClub.pl (Archived) The build was later uploaded publicly on 11 May 2020.
== Editions and keys ==
Edition / SKU Name 	Key
Core 	334NH-RXG76-64THK-C7CKG-D3VPT
Professional 	XHQ8N-C3MCJ-RQXB6-WCHYG-C9WKB
ProfessionalWMC (edition upgrade only)	GBFNG-2X3TC-8R27F-RMKYB-JK7QT
==New features and changes==
===Disk format dialog===
The disk format dialog functions again after it was broken since Windows 10 build 9785, and the option to create a MS-DOS boot disk was removed. However, it is not possible to verify that earlier builds haven't removed this option, as the option wasn't removed from the dialog, and is removed at runtime instead.
===Notification Center===
The black bar at the bottom containing the systray icons has been recolored white, matching with the rest of the user interface.
== Bugs and quirks ==
===Setup===
The Windows logo displayed in the autorun is heavily brightened and utilizes a grey background not matching with the purple one of the application.
=== Metro UI ===
Dragging a window in full-screen mode in Metro apps will result in Metro UI transitions from Windows 8.1.
=== Internet Explorer ===
F12 Developer Tools may fail to launch.
=== explorer.exe error during shutdown ===
When the system shuts down, a memory access error related to explorer.exe may occur.
=== Timebomb ===
Like other builds found in the fbl_partner_eeap branch, this build uses a test-signed certificate and as a result can be installed on the current date. However, installing this build on the current date disables the ability to change the desktop wallpaper in the Control Panel.
=== Taskbar Language Bar ===
The language bar is not displayed on the taskbar, but however the old language bar is working properly.
=== 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.
=== File operation window metrics ===
The file operation progress window (which appears while copying, moving, and deleting files) may not extend automatically when more than one operation is in progress.
=== Closing notifications in the Notification Center ===
When swiping away all notifications from a system tray application, particularly the Action Center, explorer.exe will crash.
==Gallery==
File:Win8boot.png|Boot screen
File:6.4.9821-Setup.png|Setup
File:9821-startmenu.png|Start menu
File:9821-StartScreen.png|Start screen
File:Search build-9821.png|Search and Cortana
File:Windows10-6.4.9821.0-MetroArtifacts.png|Metro visual artifacts
File:Error with window size when transferring - copying files.jpg|Incorrect file operation window metrics
File:6.4.9821-Shutdown-error.png|explorer.exe error during shutdown
File:6.4.9821-Thumbnail-error.png|Incorrect taskbar preview border color
File:Image 2023-10-08 152036815.png|Action center
File:9821format.png|Disk format dialog
===Images shared before the build was published===
File:Windows109821.png|Image posted by winclub.pl prior to being shared
== References ==
Category:Windows 10 builds