Windows Longhorn build 4002 (Lab06 N)

Windows Longhorn build 4002 is a Milestone 4 build of the Microsoft Windows Longhorn operating system. This build makes use of the Desktop Composition Engine seen in earlier Milestone 3 builds.

Unlike later Milestone 4 builds, build 4002 uses the old i386-based setup routine instead of the newer one based on the WIM installation format.

Grabberslasher first gave the details of this build on his UX.Unleaked blog. On 23 January 2020, this build was listed on a BetaArchive thread by the aforementioned user to be released to its FTP server, and was released on 31 January 2020, alongside build 4040 and build 5356. WinUnleaked also had images of this build.

This build is specific in that it was built as a private build, with binary files having the  flag set in their version information and the builder user name being present in the build tag, although the user name suggests that the build was built by the official Lab06 user account.

New features and changes

 * The new taskbar has been updated slightly, included a new clock on the taskbar, and a slightly lighter shade.
 * The sidebar has also been updated slightly, including the newer shade and slightly modified tiles.


 * A new wallpaper has been added, making this build the first Milestone 4 build to use a new wallpaper (unlike build 4001, which still uses the old M3 background).
 * MyTVApp has been removed.

Bugs

 * will throw out user registration errors upon login.
 * If Windows Explorer is restarted while an application is still open, closing the app will still have its taskbar task shown.
 * Windows may not register all available display resolutions on certain graphics hardware and driver combinations.

Installation
This build cannot be installed via a CD boot because it attempts to incorrectly load the  file. As a result, the system will BSOD after formatting the drive due to loading this file. also attempts to load this file and quits due to it, but running  can allow setup to load.

During GUI setup, there will be a copy error that it fails to copy,  , and  , the user can safely skip copying these files.

Desktop Composition Engine
Desktop Composition Engine requires either compatible hardware or VMware Workstation 6.5.x to work (just 6.5x compatibility won't work), otherwise it will result in a black screen that can only be exited by a hard reset.