Windows Vista, a new version of Microsoft's core product, could be available even later than the company says, according a leading technology analysis firm.

"We don't expect broad availability of Windows Vista until at least (the second quarter of 2007)," Gartner analysts said in a report Monday.

A Microsoft spokeswoman said, "We respectfully disagree with Gartner's views around timing of the final delivery of Windows Vista. We remain on track to deliver the final product to volume license customers in November 2006 and to other businesses and consumers in January 2007."

Microsoft shares lost 28 cents, or 1.2 percent, in regular trading to close at $24.01 TOday.

Vista, the first new version of the Windows operating system since October 2001, has already been delayed. On March 21, Microsoft announced that the product would not be available to consumers for the 2006 holiday season.

Gartner's reasoning for the estimate, which it expressed with 80 percent probability, is based on the expected ship date of the second test version of Vista, known as Beta 2. With past operating systems that compare to Vista in complexity, it took Microsoft 16 months to go from Beta 2 to manufacturing.

Microsoft has scheduled a five-month interval between Beta 2 — which perhaps 2 million people will test and provide feedback — and manufacturing for Vista.

"We believe more time is required between a stable, feature-complete Beta 2 and (manufacturing) to accommodate the issues expected during broad testing and allow for at least two (release candidates)," Gartner analysts wrote.

Microsoft expects five months to be enough because it has released preview versions of the operating system. It's planning only one release candidate.

Benjamin J. Romano: bromano@seattletimes.com

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