Windows 10 build 9845

6.4.9845.0.fbl_partner_eeap.140922-1425
	Build of Windows 10
OS family	Windows NT
Version number	6.4
Build number	9845
Build revision	0
Architecture	x86, x64
Build lab	fbl_partner_eeap
Compiled on	2014-09-22
Expiration date
Timebomb	2015-04-15 (+205 days)
About dialog

Windows 10 build 9845 is a Technical Preview build of Windows 10. It was initially shared to the public as an x64 version in the Japanese language on 2 July 2015, followed by x86 versions and other languages (including Simplified Chinese, Traditional Chinese, Korean, German, and Swedish) on 19 September 2015. The x64 English version of this build was shared on 4 November 2024.

This is the last build from the fbl_partner_eeap branch. All later available Windows 10 builds (no matter if they were originally released only to partners under the Ecosystem Engineering and Access Program, or publicly to Windows Insiders) up until the RTM (excluding build 9907 (fbl_ie) and build 10176) are flight-signed builds and have a timebomb hardcoded into the system.

Editions and keys[edit | edit source]

Edition / SKU Name	Key
Core	334NH-RXG76-64THK-C7CKG-D3VPT
Professional	NKJFK-GPHP7-G8C3J-P6JXR-HQRJR
ProfessionalWMC (edition upgrade only)	GBFNG-2X3TC-8R27F-RMKYB-JK7QT

New features and changes[edit | edit source]

User interface[edit | edit source]

The login interface has been completely rewritten, which is now invoked from LogonController.dll and Windows.UI.Logon.dll, instead of authui.dll. At this point in development, it looks similar to the existing login interface, but with the addition of a user switcher on the left side, and some differences in the sizing and positioning of various elements. It can be enabled by merging the following registry entry:

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Authentication\LogonUI\TestHooks]
"Threshold"=dword:00000001

New lock screen
New login screen

Applications[edit | edit source]

The Storage Sense page initially introduced in build 9838 is now functional. It allows the user to monitor the utilized space on a disk as well as organize it into various categories.

Main page
"This PC" option
"System and Reserved" category
"Desktop Apps" category
"Apps and Games" category
"Other user profiles" category
"Other" category
Default save locations set up

In addition to the existing PC settings application, a zPC settings application has also been included. It generally resembles the previous PC settings application, with a few differences:

The application identifies itself as "Settings", similar to later builds. Additionally, the Users and accounts category has been renamed to simply "Accounts".

zPC settings main page
Ditto, normal PC settings application

A "Corners and edges" page has been added under the PC and devices category, which allows the user to manage various settings related to window management, such as toggling the ability to show Metro apps on the taskbar and the ability to show the Charms bar by moving the cursor to the upper right corner.

Corners and edges page

The Storage Sense page, which resides in the main page in the PC settings application has been moved to the PC and devices category under a new "Disk space" name and with a few differences. The indicator at the top now shows the available disk space instead of the utilized disk space, and the file categories now shows at the main page.

Disk space page

Three new options has been added to the Search page under the Search and apps category, which is the "Use Bing to search online", "Your search experience" and "SafeSearch" options.

Search page
Ditto, normal PC settings application

Under the Network category, the Manage page has been merged with the Connections page, while the Workplace page was now much more simplified compared to its counterpart in the traditional PC settings application.

Connections page
Ditto, normal PC settings application
Workplace page
Ditto, normal PC settings application

Miscellaneous[edit | edit source]

Support for the HEVC codec has been added.

HEVC/H.265 video demonstration

Bugs and quirks[edit | edit source]

User interface[edit | edit source]

The power options in the start menu and login screen are not functional in this build.

Some Metro animations does not display properly in this build, which often results in misaligned content and/or cutoff text for a short amount of time.

Metro animation bug

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

When window auto-colorization is enabled, the borders of window thumbnails on the taskbar remain unchanged in color, even when the wallpaper is changed. This problem can be resolved by either manually adjusting the window color via the Control Panel or by performing a restart.