Microsoft investors must feel like they are staring at that little hourglass tumbling over and over on their computer screen. Should they carry on waiting in the hope that something useful transpires, or just pull the plug?

It has been quite a year so far. There has been a failed takeover offer for Yahoo, a failed buy-out offer for a bit of Yahoo, a vague alliance with activist Carl Icahn to do something about Yahoo’s board – you get the idea. Now Kevin Johnson, the head of Microsoft’s online unit – where Yahoo would have resided – has quit and Steve Ballmer, chief executive, has announced another reorganisation of the business.