RELAX, computer users, after only two weeks Microsoft will stop teasing you as the company begins the next phase of an ambitious  and risky  $300 million campaign intended to make over its tarnished image.

The campaign, which begins Thursday and carries the theme “Windows. Life without walls,” will move away from the enigmatic teaser commercials that featured Bill Gates and Jerry Seinfeld in offbeat conversations about shopping, shoes, suburbia and the potential of computing to improve life. The teaser ads have generated considerable discussion since they started on Sept. 4, not all of it positive.

What follows is an audacious embrace of the disdainful label that Apple, Microsoft’s rival, has gleefully  and successfully  affixed onto users of Microsoft products: “I’m a PC.”

One new Microsoft commercial even begins with a company engineer who resembles John Hodgman, the comedian portraying the loser PC character in the Apple campaign. “Hello, I’m a PC,” the engineer says, echoing Mr. Hodgman’s recurring line, “and I’ve been made into a stereotype.”