Spotlight On... Steven Sinofsky; Ex-Microsoft Windows chief

Steven who?

Sinofsky. You might not have heard of him, but the 47-year-old who until Monday night was the head of Microsoft's Windows division was arguably the most important person in the software giant's hierarchy after Bill Gates and the chief executive Steve Ballmer.

Windows – I read something about that recently…

That's right. Mr Sinofsky led the launch last month of the latest incarnation of the firm's core product. Windows 8 is Microsoft's bid to win back customers and the momentum lost to that Californian subversive, Apple.

And he's already been shown the door?

Well, he has, according to a memo sent round by Mr Ballmer, "decided to leave the company". It's unclear why he's gone. But, yes, it was a surprise. Mr Sinofsky has been around for about a quarter of a century, through all the highs and lows, and was tipped as a possible future CEO.

Did he do something wrong?

Nothing that outsiders can discern. He was seen as an able manager, and Windows 8 is barely out of the starting gates to be worthy of judgement.

Nothing?

The one point raised repeatedly since his surprise departure was his reputation as a polarising, often prickly figure. But this is rumour and hearsay. The suggestion is that he had the tendency to alienate people. However, in his own memo to staff, since leaked online, Mr Sinofsky said: "Some might notice a bit of chatter speculating about this decision or timing. I can assure you that none could be true as this was a personal and private choice."

So what now for Windows?

Julie Larson-Green is the new boss over there. The risk is minimised by the fact that she knows the OS well, having led the interface design for Internet Explorer, Windows 7 and 8. A long-time lieutenant of Mr Ballmer, she shouldn't have any problems finding the paper clips.