The Rise and Fall of Windows Mobile, Under Ballmer

Microsoft’s Windows Phone operating system is hardly as influential as its desktop counterpart. And now that Steven A. Ballmer has announced plans to retire, it is easy to point fingers at the Microsoft chief executive for the lackluster success the company has had in mobile computing. But that would be an inaccurate recounting of the story. Mr. Ballmer took the helm at Microsoft in 2000, just as the company was preparing to enter the mobile business with Pocket PC 2002, the earliest version of Microsoft’s mobile software.