YORK, Pa. (AdAge.com) -- "There won't be a PC sold anywhere in the world that doesn't have Vista within six months," said Endpoint Technology Associates analyst Roger

Kay, a fact that might leave ad watchers wondering why Microsoft is about to launch the product with one of the biggest marketing blitzes of all time.

'Most aggressive'
This will be the company's "most aggressive launch ever," resulting in an injection, across 20 countries, of an estimated $500 million into agency and media-owner coffers -- which seems excessive for a product that will walk out of the stores on more or less every PC sold from here on in.

But that's not the point, according to Microsoft -- which goes so far as to borrow from images such as a child discovering a snowfall, the fall of the Berlin Wall and Woodstock to persuade consumers that Vista is not just an operating system, but a potentially life-changing event. "Awareness is not enough," said John B. Williams, general manager-Windows global communications. "The goal for this campaign [is to] get at the heart of excitement."

Several strikes against it
Generating that, and maybe getting at the heart of the mammoth marketing push, may be difficult, because although the product may become ubiquitous, it starts out with several strikes against it.

First, it's from Microsoft, which detractors often paint as the monopolistic "evil empire." Then there's the fact that the product has been delayed several times and received only lukewarm reviews from analysts and beta testers. And, of course, there's Apple, which has the only other operating system.

While still a small player in the computer industry, Apple has seen its market share rise from 3% to more than 5% in the past two years, thanks in part to its iPod halo effect. "They can't take any chances or leave the field pen to Apple," Mr. Kay said. "And [Microsoft] needs to spend a fair amount of effort convincing corporate clients to buy Vista."

Difficult to explain
Last, Vista is a difficult product to explain. It's the platform on which PCs run, but the user doesn't really see it. Marketing will help explain what Vista is and does. Some TV ads, for instance, feature 3-D flip screens with the Windows Vista border around the edge of the screen for the duration, showcasing the new Vista look.

"The last time people made a decision on an operating system was five years ago -- and the world has changed dramatically since then," Mr. Williams said. "We have to show the product because when they see Windows Vista, they'll get it ... and have this kind of reaction we're looking for."

And the reaction it's aiming for: "Wow."

"This one word kept coming out as people sat down and played with the product," said Mike Sievert, corporate VP-Windows client marketing. "The campaign concept works very well across cultures and geographies." (Vista will have a "big advertising presence" in 20 of its 50 markets.)

6.6 billion impressions
Indeed, the planned scope of the campaign -- 6.6 billion impressions in its first few months -- is wondrous by today's narrowly targeted, niche-media standards. "The Wow starts now," two years in the making with McCann Worldgroup, encompasses an online consumer-participation promotion themed "Show us your wow" (the winner gets a trip around the world), sponsored webisodes at Clearification.com featuring "Daily Show" comedian Demitri Martin and an alternate-reality game called "Vanishing Point" that moves between online and offline.

A human billboard will feature 16 dancers forming the Vista and Microsoft Office icons, and Microsoft Chairman Bill Gates himself will host an invitation-only party in Times Square. A slew of retail promotions are set for Jan. 30 in more than 30 markets around the country and will include Xbox giveaways and school PC-lab makeover sweepstakes, as well as rebates and special deals. Microsoft experts will be on-site to answer questions. Microsoft CEO Steve Ballmer will greet customers at Best Buy in New York.

But it's the TV ads that will garner much of the attention-and inevitably it won't be all good. The spots picture "Wow"-murmuring moments such as a '60s-looking family staring at a black-and-white TV as a rocket blasts into space, a hippie climbing up on scaffolding to look out over the Woodstock crowd, a young boy staring out his window at a early-morning snow-blanketed street, and a man putting down a chunk of rock on the table as those gathered watch the Berlin Wall being torn down on TV. The juxtaposition will provide surefire fodder for the blogosphere.

LeBron James
Basketball superstar LeBron James also lends his celebrity to the ads. In a vignette, he is playing with a group of kids when one breaks in front of him, zipping off and doing fancy dribbles down the court. Mr. James stares after him and says "Wow." At the end of every spot, a man opens his laptop in a darkened office while the voice-over intones, "Every so often you experience something so new, so delightfully unexpected, there's only one word for it."

Cue the Vista "Wow."