If Vista “gets a long enough life cycle, it will not be remembered like Millennium Edition,” he said.

That life cycle is looking somewhat shorter than XP’s. Microsoft Corp. chairman Bill Gates said recently that the new version of Windows’ operating software, code-named Windows 7, will be released “sometime in the next year or so.”

In the meantime, the company is facing a class-action lawsuit in federal court over the way it advertised computers sold with XP as being capable of running Vista.

Among them, the company said earlier this month it will keep selling a version of XP for use on new, low-cost computers, such as Intel’s Classmate PC, through at least June 2010. Such computers are designed mainly for word processing, e-mail and Web surfing.