Windows 8 build 7850

Windows 8 build 7850 is a Milestone 1 build of Windows 8. It was the first leaked version of Windows 8 on 2011-04-12. Initially, this build only leaked as an Enterprise SKU image. Only much later, in January 2015, additional SKUs leaked.

Being early in development, many areas still says Windows 7 and the kernel is still 6.1 (in a similar manner to XP build 2202 and build 2211). The default background image of this build is a blueish gradient with the note not to leak this version ("shhh... let's not leak our hard work").

Features
Note: Most new features must be unlocked via Registry editing.
 * Explorer Ribbon UI (Icons are all circles)
 * Centered Title Bar Text
 * Built-in PDF Reader (basic)
 * New/Modern Task Manager (partially broken)
 * Webcam Application (fullscreen)
 * AutoColorize Themes
 * ApplicationExplorer (for early start screen?)
 * AeroLite (basic)
 * Early beta of IE9
 * System Reset (sysreset.exe)
 * Portable workspace creator (pwcreator.exe)

Aero
This build appears to have a slightly broken Windows Aero theme, with only the top portion of the window frame using the blur effect, leaving the side borders transparent.

PDF Reader
While there is a very early version of the built-in PDF Reader included, it is disabled by default. It can be enabled using the following registry script: Windows Registry Editor Version 5.00 [HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Applets\Paint\Capabilities] "CLSID"="{D3E34B21-9D75-101A-8C3D-00AA001A1652}" and then running  with any PDF file as an argument (or without any argument to open a blank page). According to the article about the build on The Collection Book you should disable Aero to get this to work, but we found this step to not be required.

Modern Windows Task Manager
A preliminary version of the Modern Windows Task Manager is included as well. To enable it, run the following registry script: Windows Registry Editor Version 5.00 [HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\TaskUI] "TaskUIEnabled"=dword:00000001 and then open.

Ribbon UI
A Ribbon version of Windows Explorer is included as well. To enable it, use the following registry script: Windows Registry Editor Version 5.00 [HKEY_CLASSES_ROOT\CLSID\{4F12FF5D-D319-4A79-8380-9CC80384DC08}] "AppID"="{9198DA45-C7D5-4EFF-A726-78FC547DFF53}"

Webcam Capture Application
An early version of the webcam capture application is included as well. To enable it, run the following registry script: Windows Registry Editor Version 5.00 [HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\GRE_Initialize] "RemoteFontBootCacheFlags"=dword:0000100f and then run.