Windows Longhorn build 4089

Windows "Longhorn" build 4089 is a Milestone 7 build of the Microsoft Windows "Longhorn" operating system.

One screenshot of this build has been released, which shows a prototype version of Windows Movie Maker based on Windows Presentation Foundation.

In the BetaArchive topic "New Longhorn builds for a new decade" by Grabberslasher on 2020-01-23 where more than 35 Longhorn pre and post-reset builds were leaked, including all then-unleaked builds showcased on UX.Unleaked, ReflectiaX mentioned that he once had a copy of this build, or at least another 4089 numbered build, but had since lost it.