Windows 10 build 9879

6.4.9879.0.fbl_release.141103-1722

Build of Windows 10
OS family	Windows NT
Version number	6.4
Build number	9879
Build revision	0
Architecture	x86, x64
Build lab	fbl_release
Compiled on	2014-11-03
Expiration date
Timebomb	2015-04-15 (+163 days)
About dialog

Windows 10 build 9879 is the third officially released Technical Preview build of the original release of Windows 10. It was released to Windows Insiders in the Fast Ring on 12 November 2014 and to Windows Insiders in the Slow Ring on 25 November 2014.

Editions and keys

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
Enterprise	PBHCJ-Q2NYD-2PX34-T2TD6-233PK

New features and changes

• Battery icon is now thinner and flatter in appearance.
• Action Center was renamed to Security and Maintenance.
• Feedback button (in the form of a smiley face) has been added to Internet Explorer 11.
• OneDrive received improvements.
• UWP login screen's font now uses Segoe UI unlike build 9860.
• XAML start menu is now displayed correctly.

Findings

Hidden features

The following hidden features have been found within this build:

• Hidden lock screen - enabled by setting Threshold to 1 under [HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Authentication\LogonUI\TestHooks] in the registry like in build 9845.
• XAML Start menu - create and set UseExperience to 1 under [HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\ImmersiveShell\Launcher]
• Search box on the taskbar - enabled by setting EnableSearchBox to 1 under HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Search. The search box's font is vgasys.fon at this point in development.

Hidden apps

There are a few hidden apps in this build:

• Windows Default Lock Screen - accessed by running C:\Windows\explorer.exe shell:AppsFolder\Microsoft.WindowsDefaultLockScreen_8wekyb3d8bbwe!LockApp
• Cloud Experience Host - accessed by running C:\Windows\explorer.exe shell:AppsFolder\Microsoft.CloudExperienceHost_8wekyb3d8bbwe!App
• Windows Shell Experience Host - accessed by running start-menu://test/

Bugs and quirks

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.

Gallery

Setup

• 

  Boot screen

• 

  Setup

• 

  EULA

• 

  OOBE

• 

  Account creation

• 

  Post-OOBE

Interface

• 

  Start menu

• 

  winver and a notification toast

• 

  Notification Center

• 

  Smile Feedback button on IE

• 

  Clicking on the button

• 

  Incorrect window thumbnail border color

• 

  winver of the debug compile

• 

  Demo

Hidden features

• 

  XAML start menu

• 

  Desktop with search box enabled

• 

  Hidden lock screen

Updates

• 6.4.9879.2.fbl_release_currentfr.141107-1950 - KB3016656/3016725
  • Released 11 November 2014
• 6.4.9879.3.fbl_release_currentfr.141118-1627 - KB3019269
  • Released 24 November 2014
• 6.4.9879.4.fbl_release_currentfr.141120-1731 - KB3018943
  • Released 25 November 2014
• 6.4.9879.5.fbl_release_currentfr.141124-1731 - KB3020114
  • Released 1 December 2014
• 6.4.9879.6.fbl_release_currentfr.141125-1839 - KB3021937
  • Released 9 December 2014
• 6.4.9879.7.fbl_release_currentfr.141202-2315 - KB3022827
  • Released 9 December 2014 as an additional update to KB3021937
• 6.4.9879.8.fbl_release_currentfr.141205-1804 - KB3024666/3025096
  • Released 15 December 2014