Satya Nadella: As Windows 10 is launched can he return Microsoft to its former glory?

There was a time when the launch of a new version of Windows, Microsoft’s ubiquitous PC operating system, was a matter of great anticipation. People queued up outside shops, just as they now queue up for the latest iPhone. So low has Microsoft’s light dimmed in recent years that last week’s launch of Windows 10 came with a whimper, not a bang – even if it was relatively well received by software critics.