Neptune and Odyssey
Occasionally, artwork appears for internally developed versions of Windows, that were never or still have yet to be commercially released, such as those with the project names Blackcomb, Odyssey, and Windows Neptune.
Neptune was to have been the Home Edition of Windows 2000, but was dropped as a release project in favor of Windows ME. The currently preferred OS-tan character design has her resembling an Android from the online game Phantasy Star Online. She is easily recognized by the visor she wears, and a Shinto O-fuda demon-protection charm being used to keep her banished from the real world.
Odyssey, the second attempt at a Home version of Windows 2000, appears as a senior high-school girl in a blue-themed uniform, wearing glasses and a gold CDR disc as a hairpiece or halo. As this operating system was never formally published, its release was limited to an impromptu supply from the developers' own desktop CD burners, using gold CDR blanks.
(The third attempt to merge the functionality of the Windows NT and Windows 9X Operating Systems into a single product, project Whistler, is better known today as Windows XP.)