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 3706 and 3718, which makes it one of the last builds to use full DCE in the M4 stage.

Unlike later Milestone 4 builds, build 4002 uses the old setup based 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 gave the details of this build on his UX.Unleaked blog. On 2020-01-23, he leaked it to BetaArchive. WinUnleaked also had images of the build.