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 is one of the earliest to introduce the Plex theme and the Windows Sidebar. One of the notable changes was that the Windows logo was only white, not colored like all the versions of Windows before it. 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. Contrary to popular belief, this build already contains Desktop Composition Engine, but it is unstable and only renders window transparency. This build is one of the first to feature four virtual desktops. The OOBE music is also changed to "No Hay Problema" from Pink Martini, and it is possible to terminate critical system processes in Task Manager.

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. 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.

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.