More than a year before Windows Vista's release—and long before Apple started poking fun at the operating system—Microsoft officials were already worried about comparisons between Mac OS X and Vista, insider e-mails disclosed yesterday revealed.

An e-mail thread from October 2005, more than 15 months before Vista debuted, showed that an article in the Wall Street Journal by columnist Walter Mossberg grabbed the attention of managers at Microsoft. In a column headlined What PC to Buy If You Are Planning On a Vista Upgrade, Mossberg spelled out his recommendations for a desktop PC, focusing on the features buyers should keep in mind if they wanted to run Vista when it hit the street.

But one paragraph caught the eye of Padmanand Warrier, a developer in the Windows group. Warrier e-mailed a link to Mossberg's column to several others in the company, including Rajesh Srinivasan—at the time a product manager in the Windows group—and Richard Russell, a Microsoft development manager. Warrier quoted briefly from the Mossberg piece.

"You won't have to worry about Vista if you buy one of Apple Computer's Macintosh computers, which don't run Windows," Mossberg had written. "Every mainstream consumer doing typical tasks should consider the Mac. Its operating system, called Tiger [at that time, the most-current Mac OS X -- Ed.], is better and more secure than Windows XP, and already contains most of the key features promised for Vista."

Warrier added a comment of his own. "A premium experience as defined by Walt = Apple. This is why we need to address [the column]."

That got an almost-immediate rise out of Russell, who acknowledged that Microsoft had not done its job in promoting Windows Vista. "My take away from Walt's article is that we have failed to communicate Vista's value," Russell said in an e-mail reply sent just 20 minutes after Warrier fired off his.

Russell went on to defend Vista, specifically its ability to "run on a very wide ranging set of systems from the minimally capable to the incredibly capable," he said. "Apple doesn't do that."

He also touched on the idea of a Vista "premium" experience, which led him to a discussion of "Vista Ready," the name of the marketing campaign that would later be recast as "Vista Capable" and become the focus of the class-action lawsuit that led to his message going public.

"Vista Ready means that a PC will run Vista well—it doesn't mean the users will get a 'premium' experience—it never has meant that," Russell said. "There was some thinking and effort put into having a higher tier Vista Ready logo, but this didn't fly with the OEMs.