It’s a brisk day at Microsoft headquarters in Redmond, Washington, just outside of the city of Seattle. The air is cold and crisp and there’s frost under the trees well into the afternoon. But the sky is clear, and the view of Washington state and America beyond from its great glass picture windows is not to be missed. There had been a change in the weather. Just the day before, Seattle was smothered in a deep, thick fog that made air travel and driving damn near impossible. It also served up a nice, writerly metaphor for a meeting with Satya Nadella on the occasion of rounding out his first full calendar year as the CEO of Microsoft. (A job he started in February of 2014.) It’s a tough gig. Microsoft was once the company that you used, if you used a computer at all. But it has lost that vitality, and as the industry transitioned to mobile the company has often seemed adrift. In 2012, Vanity Fair made a convincing case that Microsoft had suffered a “ lost decade .”(By the next year,...