Microsoft last week revealed that Longhorn will be called "Windows Vista" - and may need to visit the courts to justify its use of the name.
The Redmond-based company has annoyed a near neighbour: long-established business software maker, Vista.
Also based in Redmond, Vista was founded in 1999 by John Wall, described as a, "well-known technology executive in the area", by The Seattle Times.
Vista is "examining" Microsoft's chosen name in order to assess whether it violates the company's six-year old trademark. Wall will speak with Microsoft on the matter, and is prepared to resort to court action to protect his business.
In the Internet age, original names are becoming increasingly hard to find, and given Microsoft's market position, some analysts don't think the name matters too much.
Naming Company owner David Burd told The Seattle Times: "If Microsoft called it Windows Garbage, would people still buy it? Yeah, they'd buy it. They've got something like 90 per cent penetration in the world of operating systems."
Microsoft clears it up
Greg Sullivan, group product manager in the Windows client division said the name reflects Microsoft's focus for the release of, "bringing clarity to the world so you can focus on what matters to you."
Issues between Vista and Microsoft need to be resolved fast - Microsoft plans massive marketing using the name next year, as it sets the scene for the new operating system's debut by August 3, 2006.
What's in a name?
Wall warns that the name "Vista" to be a "tricky choice", because, "many companies claim trademarks on various uses of the word".
Microsoft counters that it is attempting to trademark the use of the term, "Microsoft Vista", and that other uses of the word Vista are not part of the company's strategy.
The Redmond software giant may have missed a trick: the company has "missed a chance to create a unique name".