A federal judge this afternoon denied, for the most part, Microsoft's motion to dismiss a proposed class-action lawsuit over the "Windows Vista Capable" and Express Upgrade programs used to market Windows XP machines last year.

The ruling by U.S. District Judge Marsha Pechman means that at least two of the plaintiffs' claims in the case will proceed -- the allegations that Microsoft's marketing violated the Consumer Protection Act, and that the company was unjustly enriched. Pechman reserved judgment on a third claim, the allegations that the company violated federal warranty law, saying she would issue a written ruling on that matter in about two weeks.

The outcome is not a complete surprise: It's not unusual for a case to survive a motion to dismiss, which is one of the first challenges faced by a lawsuit. For purposes of the motion, the judge assumes the alleged facts to be true, and then decides whether the plaintiff's case is legally sufficient to proceed.

See this earlier post for background. The case focuses primarily on the stickers that touted Windows XP machines as "Windows Vista Capable," with the specifications needed to run the new Microsoft operating system when it was released in January. The suit alleges that the stickers were deceptive because many of those XP machines were capable only of running Windows Vista Home Basic, which doesn't include many of the highly touted features available in advanced versions of the operating system.

A lawyer for Microsoft, Stephen Rummage of law firm Davis Wright Tremaine, argued in court that the lead plaintiff in the case, Dianne Kelley of Camano Island, did not make allegations sufficient to show that she was harmed by any of Microsoft's actions, or even influenced by the "Windows Vista Capable" labels. In addition, he challenged the allegation that the machine she bought was not capable of running Windows Vista.

"It runs Vista," Rummage said. It just "doesn't run the version of Vista that they wish it did," he explained. That, he said, is the essence of the complaint.

Plaintiffs' lawyer Jeffrey Tilden, of Gordon Tilden Thomas & Cordell, said the "Windows Vista Capable" stickers were affixed to machines that can't perform many of the features by which people have come to define Windows Vista. Examples include the remote-controlled Windows Media Center interface and "Flip 3D" window-switching.

"Microsoft defined the terms of this bargain: 'You're going to get this Windows Vista capable machine and at some point in the future you're going to get the remainder of this promise,' " Tilden said. "Then they didn't deliver the promised product."

Future stages in the case will include a motion for class certification, seeking to open it up to other consumers who bought machines under similar circumstances. A trial, if it comes to that, is scheduled to take place in October 2008.