Windows Longhorn build 3663

Windows Longhorn build 3663 is an unconfirmed and controversial build of Windows Longhorn. It is the earliest known build for which screenshots exist. A rumor exists that the build was shared online in the past, but due to low interest, the download links were permanently removed. There is no evidence to support this rumor, however, and it can be safely assumed that there was never any release beyond a few screenshots.

Visual changes in the build include the replacement of the colored Windows flag on the start button with a single white color variant, along with the default including Longhorn branding. It also seems to have the login screen from build 3683 and disk space indicators in Explorer. Otherwise, this build is not much different from Windows XP or Windows Server 2003. It is unknown if this build has the Plex theme due to the theme in the screenshots being set to the Silver variant of Luna, nevertheless, judging by the screenshot of the explorer, it can be judged that there is probably no Plex theme and interface.