Windows 10 build 9780

Windows 10 build 9780 is the earliest available build of Windows 10, which was uploaded to BetaArchive on 26 January 2019. This build was originally released to Microsoft partners participating in the Ecosystem Engineering Access Program (EEAP), as indicated by the  branch.

Due to its earliness, this build identifies itself as Windows 8.1 in many areas and still bears the 6.3 kernel version.

Start menu
A new Start menu has been introduced, merging the Windows 8 and Windows 7 styles. The Start screen from Windows 8.1 can be brought back when enabling the full screen option in the Start Menu Properties.

Window animations
DWM-based window animations (particularly when opening and closing windows) have been changed to simpler transitions.

Jump Lists
The Jump Lists appearance on the taskbar now changes color according to the user's accent color. However, restarting  will revert it back to window coloring.

Desktop backgrounds
This build retains the same set of desktop backgrounds as Windows 8.1, except that  and   backgrounds have been swapped, resulting in Windows 8.1's   becoming the default background.

File Explorer
File Explorer received a new page called Home, which opens when the user launches the app.

PC Settings

 * The option to enable Battery Saver has been added to PC Settings.
 * The "Flights" page has been added, which would later be used for configuring Windows Insider builds.

OneNote
The Metro OneNote app from Windows 8.1 Update 1 is no longer installed by default.

Windowed Metro applications
This build introduces native support for Metro apps in windowed mode, which is disabled by default. It can be enabled by merging following registry setting:

However, title bars will use the same style as Win32 applications. Also, the feature itself has bugs.

Search
This build includes a nonfunctional Search utility, which is disabled by default. It can be enabled by merging following registry setting and restarting File Explorer:

Timebomb
Like other builds found in the  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.

Compatibility
Attempting to install this build through VMware Workstation by using the Easy Install mechanism will lock the newly created user account out with a password expiration warning. It can be remedied by adding a password to the user during the VM creation process.

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.

Safe mode
Trying to boot into safe mode (whether via System configuration tool or Recovery Options) results in a black screen.