Windows Longhorn build 4067 (private/lddm dev tech(davidmo))

Windows Longhorn build 4067 (private/lddm_dev_tech(davidmo)) is a private Milestone 7 build of Windows Longhorn. It was shown during WinHEC 2004 when Jim Allchin used it to demonstrate the then-new Longhorn Display Driver Model (later known as the "Windows Display Driver Model").

A presentation photograph featuring two screenshots of this build and a screenshot of an unknown Aero demo build shown at WinHEC 2004 were first shared by LucasB on 26 May 2021 — a high resolution version of the two screenshots were later shared by ReflectiaX (aka BetaCollector) on the same day.

The build tag was for many years incorrectly stated on build lists as 6.0.4067.private/lddm_dev_tech(devdmo).040212-1646, a misreading of the username "davidmo" interpreted to mean "development demo".