Microsoft has reportedly earmarked $500m for a massive global advertising campaign to support the launch of its new Vista operating system.

In what will be its “most aggressive launch ever”, Advertising Age said the Redmond, Washington, giant is launching a campaign across 20 countries that aims for “6.6bn impressions in its first few months”.

The theme for the campaign is “wow”, said Windows marketing VP Mike Sievert – TV advertisements will include historical moments like Woodstock, a child’s first snowfall and the fall of the Berlin Wall, juxtaposed with Vista’s new Mac-like 3D window shuffling capabilities.

Microsoft previously spent $300m marketing Windows 95 and $500m on the Windows XP launch, according to reports.

At a campaign launch for the new product yesterday, a huge Vista banner was unveiled, Cirque du Soleil-style, in New York before the company partied with local beta testers in Times Square. Bill Gates appeared on ABC’s morning Today show as well as The Daily Show.

Microsoft chief executive Steve Ballmer said Vista would be “the biggest launch in software history”, adding he expected to double the sales of Windows Xp.

The company last March said it was spending the same amount on a campaign to win over business software customers.