Microsoft on Thursday announced it is moving to the next phase of its $300 million ad campaign to reboot its image and promote Vista, the company’s latest and much-criticized operating system.

The first two ads by the software giant featuring odd duo Bill gates and Jerry Seinfeld were received very coldly by critics and viewers alike and there is speculation among tech bloggers that the comedian’s contract was canceled prematurely due to his lack of appeal.

The company refutes that there was a brusque ending, preferring to say instead that the two “Bill and Jerry” ads–for which Mr. Seinfeld received a generous $10 million--were intended as a teaser.

“The Bill-and-Jerry ‘teaser’ ads give way to a new series of television ads that celebrate the diversity and passion of consumers around the world,” the Redmond, Washington, company said in a statement.

The “next phase” of the campaign will star a weird panel of celebrities, including actress Eva Longoria, astronaut Bernard Harris, and author/spiritual guru Deepak Chopra, “all celebrating the sense of power and community Windows enables by declaring: ‘I am a PC,’” said the company.

An email to Microsoft to ask how much the various celebrities were paid to celebrate Windows was not answered.

The “I am a PC” campaign seems to come as a late retaliation against the popular “Mac vs. PC” campaign launched in 2006 by longtime rival Apple, in which a cool and tech-savvy Mac guy ridicules a plump and boring PC geek, portrayed as an eternal looser.

“Whether the campaign transition was planned or not, Microsoft's advertising seems to be all over the place of late,” ad industry publication Advertising Age wrote.

Another element of Microsoft’s belated “phase 2” also makes it possible for Windows users to create their own spots.

“We're enabling every PC user to upload their own I’m a PC spot,” some of which will be posted on billboards in Times Square, said the company.

Microsoft’s $300 million ad campaign developed by advertising firm Crispin Porter and Bogusky to revive the software giant’s tarnished image--the most expensive in the company’s history--“is a long-term marketing investment for the company,” Bill Veghte, senior vice president of online services and Windows business, said in a statement.

One only hopes that the “second phase” of the expensive campaign to save Windows will be more successful than the short-lived phase 1, virulently booed by critics.

Windows Vista is Microsoft's biggest moneymaker--accounting for 28 percent of the company’s $60.4 billion in revenue last year.

Microsoft’s stock climbed 2.77 percent to $25.25 in the Nasdaq Stock Market. The shares have dropped 28 percent so far this year.