Steven Sinofsky, the head of Microsoft's Windows division, has left the company with immediate effect.

His departure comes just weeks after Microsoft launched Windows 8, the latest edition of its flagship product, seen as key to the firm's future.

Microsoft did not give any reason for Mr Sinofsky's departure.

However, one industry watcher suggested there had been talk of an internal "war" between Mr Sinofsky and chief executive Steve Ballmer.

The company said Julie Larson-Green would be promoted to lead all Windows software and hardware engineering.

BBC News