Ballmer on Ballmer: His Exit From Microsoft

"Maybe I'm an emblem of an old era, and I have to move on," the 57-year-old Mr. Ballmer says, pausing as his eyes well up. "As much as I love everything about what I'm doing," he says, "the best way for Microsoft to enter a new era is a new leader who will accelerate change."

Mr. Ballmer, in a series of exclusive interviews tinged with his characteristic bluster and wistfulness, tells of how he came to believe that he couldn't lead Microsoft forward—that, in fact, Microsoft would not be led by him because of the very corporate culture he had helped instill.