By Aidan Malley

Published: 05:50 PM EST

Having lost its patience with Apple's "Get a Mac" advertising campaign attacking Windows Vista's public perception, Microsoft will spend hundreds of millions of dollars trying to prop up the standing of its operating system.

The company's VP of Vista marketing, Brad Brooks, told attendees at a Microsoft Worldwide Partner Conference on Tuesday that the next few months will see a major advertising push that promises to "free the people" through what Vista has to offer and that Microsoft wouldn't take Apple's repeated attacks on Vista reliability without a fight.

"You thought the sleeping giant was still sleeping, well we woke it up and it's time to take our message forward," Brooks warns Apple. "There's a conversation going on in the marketplace today and it's just plain awful. We've got to get back on the front foot."

He acknowledges, however, that Vista's rough launch has cost the company significant ground and that the ads will as much be about damage control as touting the brand. In a rare glimpse into Microsoft's own view of the launch, Brooks recognizes that Vista "broke a lot of things" and triggered "a lot of pain" in partners trying to support the newer Windows edition.

According to the executive, difficulties with new operating system launches are common and a similar pattern emerged with Windows XP in 2001, which eventually smoothed out as patches and gradual acceptance made it the dominant operating system. Recent updates to Vista have ironed out similar wrinkles, he argues.

By contrast, Apple is said to be "noisy" in controlling the message on Vista. The Mac maker has regularly pointed out flaws and stressed that many users are looking to downgrade to XP after sour experiences with Vista. To Brooks, though, Apple is pitching an all-or-nothing message for its products that Microsoft can counter with perceived choice.

"They tell us it's the iWay or the highway. We think that's a sad message," he says. "Software out there is made to be compatible with your whole life."

Whether or not Microsoft will succeed in its mission, however, is less than clear. Businesses have commented that they consider it impractical to upgrade to Vista due to compatibility problems and may wait until Windows 7 to update past Windows XP, a move that would delay any purchases until at least 2010.

Also, in the prelude to Microsoft's ad campaign, Apple is still believed to be stealing away those Microsoft hopes to win over: a Bank of Montreal estimate has as many as 2.5 million Macs shipped in the current quarter based partly on users opting for Apple's platform rather than face the concerns raised by Vista.