Windows 8 build 7850

Windows 8 build 7850 is a build of Windows 8, which was originally uploaded to BetaArchive as an x86 Enterprise SKU version on 12 April 2011, then on 17 January 2015, an x64 version of this build was uploaded to the aforementioned website along with additional SKUs for both the x86 and x64 architectures and its server counterpart. It is the earliest known x86 leaked build of Windows 8.

Being early in development, many areas still say "Windows 7" and the kernel is still 6.1 (much like the earlier builds 7700 and 7746). The default background image of this build is a bluish gradient with a green tint at the lower right and a message at the top telling users not to leak this build ("shhh... let's not leak our hard work").

Redpill
The 2 March 2020 build of Redlock unlocks various features in this build. It is the earliest available build to implement Redpill.

The Start screen in this build is rather primitive, having only one view featuring every installed application with a tile. It also includes a button to bring up an early search pane. A very early and non-functional snap UI is seen when you exit from the Start screen. A primitive Charms bar is also implemented and is accessible by pressing Win + C on your keyboard, but it is non-functional. New folder icons, along with a preview grid, are present in this build when Redpill is enabled.

For an unknown reason, in Checked/Debug compilations of this build, the Start screen has a yellow-orange background instead of the white background seen in free compiles.

Other features include:


 * Support for 32-bit UEFI boot
 * Support for booting from an exFAT partition
 * 4K Native logical sector boot
 * Hybrid boot
 * Explorer Ribbon UI (icons are all circles)
 * User tile (located at the right of the taskbar)
 * Centered title bar text
 * Explorer up button
 * Built-in PDF Reader (basic)
 * Modern Task Manager (partially broken)
 * Webcam Application (full screen)
 * Built-in virtual optical drive (double-click the ISO file to directly mount the image)
 * Auto colorization of themes
 * ApplicationExplorer shell location (Applications.{4234d49b-0245-4df3-b780-3893943456e1}) - tabs include "Tile state" and "Host environment". This is where the Start screen app list is stored, even up to 8.1.
 * Aero Lite (labeled "Windows Classic")
 * Early beta build of IE9
 * Built-in USB xHCI drivers
 * Built-in UASP drivers
 * Certificates and digital signatures that recognize the SHA256 algorithm
 * New Disk Cleanup
 * System reset
 * Portable Workspace Creator
 * Each user's desktop wallpaper will also be applied to the lock screen for that account.
 * Hyper-V has been introduced in the Professional and Ultimate SKUs.

PDF Reader
There is a very early version of the Immersive Reader included, accessible by running  with any PDF file as an argument (or without any argument to open a blank page).

Modern Windows Task Manager
A preliminary version of the Modern Windows Task Manager is included as well. It is accessible by running.

Ribbon UI
A Ribbon version of Windows Explorer is included as well. However, most of the icons for it are placeholder circle icons.

Webcam Capture Application
An early version of the webcam capture application is included as well, accessible by running.

Auto Colorization
Create a copy of a theme from, add   to the end of the   section and apply.

Miscellaneous
The Getting Started application from Windows 7 has been removed.

General

 * On some machines, it is not possible to install this build due to a  bugcheck.
 * Some graphics drivers may prevent the system from booting and will result in an  bugcheck.

Installation

 * On some machines, it is not possible to upgrade to this build due to an error when booting into the OOBE.
 * The messages shown when the setup is starting or restarting the computer are cut off.
 * The original upload of this build from 2011 is bundled with the Windows 7 RTM pre-installation environment.
 * Setup may hang when restarting after the hardware portion. Resetting the machine will fix the problem.

Windows Basic
The Windows Basic and the High Contrast themes are broken.

Explorer

 * Changing the date has a chance of crashing the Explorer shell.
 * Using Desktop Gadgets significantly slows the OS down.

Timebomb

 * The timebomb is broken, so the build can be installed on the current date. Doing this will cause Windows to not be activated though.

Windows Aero

 * Aero will have a black screen when running VMware Workstation version 14.0 or above.