Windows Longhorn build 4020

Windows Longhorn build 4020 is a Milestone 5 build of Windows Longhorn. A screenshot of the build was leaked on the BetaArchive Discord on 2018-11-27. Longhorn.at.ua also have a few images of this build. On 2018-12-03, this build leaked to BetaArchive FTP by ReflectiaX.