Windows Longhorn build 3683

Windows Longhorn build 3683 is a Milestone 3 build of Windows Longhorn and is currently the earliest leaked build of Longhorn. The build was leaked in November 2002 by XBetas, and their effect can be seen in the setup handle (advertising for their now long-gone IRC channel). The pure unmodified copy of this build isn't leaked, but it is believed that some private beta scene members have it.

This build still uses the i386 installation used in previous versions of Windows (and as such still has the same minimum requirements as Windows XP). However, using  to install has been unsupported and no longer works.

New features

 * This build is one of the earliest to introduce the Plex theme and the Windows Sidebar.
 * The Windows logo in the Start Button has been changed to be all white, and not colored like all the versions of Windows before it.
 * The login screen has been modified from the blue Luna color to a white and dark blue color. The current date and time is also included on the top right corner of the login screen.
 * Windows Explorer has been partially changed, like the templates in the My Documents and My Pictures were notably different as well as the Open and Save as dialog boxes also included the template, incorporating aesthetic changes and a few new user interface options.
 * This build also includes a display settings applet based on the Windows Presentation Foundation (then codenamed Avalon).
 * Internet Explorer has been updated to version 6.05 as well which includes a download manager.
 * This build is one of the first to feature virtual desktops. This was also later introduced in Windows 10, but unlike in Milestone 3 of Longhorn, it's unlimited and can't have different wallpaper anymore.
 * The OOBE music is also changed to "No Hay Problema" from Pink Martini, which is also included but not used in Windows Server 2003.
 * It is possible to terminate critical system processes in Task Manager.
 * This build's watermark refers to itself as "Longhorn XP Professional" as opposed to "Windows XP Professional" on the earlier builds.

Desktop Composition Engine
Contrary to popular belief, this build already contains Desktop Composition Engine, but it is unstable and only renders window transparency. It is only known to work on real hardware, and it lacks a user interface as well. It can be enabled by adding the following registry key, rebooting, and then running the command : Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\DesktopComposition] "StartupOptions"=dword:00000001

WinFS
An early revision of WinFS was also included, but very little in the way of a user interface was included, and as such it appeared to early testers to be nothing more than a service that consumed large amounts of memory and processor time.

Windows Sidebar
This build was one of the earliest to include the Sidebar. A new "Sidebar" was also present, which contained many of the gadgets that would much later be seen in Windows Sidebar, such as an analog clock, slide show, and search capability. An option in this version of the sidebar also made it possible to move the Start button into it, and disable the traditional taskbar entirely.

Bugs and quirks

 * As stated above, this build can no longer be installed by running  from MS-DOS.
 * As with later builds of Longhorn, this build is incompatible with a number of applications that require Windows XP or earlier due to the kernel version. Many of these compatibility issues can be resolved by running applications in Windows Compatibility Mode or by editing the CSDVersion key located in the Windows Registry.
 * Although this build is stable when compared to later builds of "Longhorn", Windows Explorer is a bit unstable and often will fail to terminate upon ending the user session.