Thats according to sources close to the company who requested anonymity. They said Microsoft unveiled the name Thursday in Atlanta at the companys internal sales event, known as the Microsoft Global Sales Briefing, or MGB.
Word of Longhorns new name began leaking to the Web on Thursday evening.
One Windows site discovered that Microsoft registered the WindowsVista.US domain name. Microsoft is expected to make the official announcement on the new name Friday morning.
Microsoft has relied primarily on date-oriented names for many of its products, although it has shied away from those on occasion.
The last major version of Windows, code-named "Whistler," eventually was christened Windows XP.
Microsoft officials declined to comment on the specifics of a "Longhorn-related" news announcement slated for Friday morning.