Microsoft has had many ideas over the years that reached their beta stages but never made it to official Windows builds. One of those projects was a self-hosting mechanism from a Windows build in 1999 which was codenamed Neptune according to Albacore.

What makes this screenshot special is that it shows the Neptune upgrade service which is not just a program update but an update that would completely update the Windows operating system build number, which is more the equivalent of what you would get from being a Windows Insider today.

Windows Millennium Neptune upgrade service
This self-hosting mechanism in Windows Neptune from 1999 shows the Neptune upgrade service which is the equivalent of the Windows operating system of today updating a Windows insider build.

Neptune largely resembled Windows 2000, but some of the new features introduced, such as the firewall, were later integrated into Windows XP as the Windows Firewall. Neptune introduced a logon screen similar to that later used in Windows XP. Neptune also experimented with a new HTML and Win32-based user interface originally intended for Windows Me, called Activity Centers, for task-centered operations.

Windows Neptune was a version of Windows that some say superseded Windows XP, but that can’t be the case if XP arrived in 2001. Rather, Neptune and Odyssey were combined to create Windows XP. Neptune was only the codename for the Windows operating system that was being developed in 1999; it was based on Windows 2000.

Eventually it was Windows Vista that offered what Microsoft was working on with Windows Neptune here.

Via: Albacore

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