Windows Longhorn build 4002 (Lab06 N)

Windows Longhorn build 4002 is one of the first Milestone 4 builds 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. This is the first Milestone 4 build to use the new background unlike build 4001, which still uses the old M3 background.

Grabberslasher first gave the details of this build on his UX.Unleaked blog. On 2020-01-23, this build was listed on a BetaArchive thread by the aforementioned user to be released to its FTP, and was released on 2020-01-31, alongside build 4040 and build 5356. WinUnleaked also had images of this build.

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.