You're right about Windows being very profitable up till now, but there's something clever in this idea... Businesses pay for Windows, but ordinary consumers b

You're right about Windows being very profitable up till now, but there's something clever in this idea... Businesses pay for Windows, but ordinary consumers by and large don't, they get it for "free" when they purchase a computer. But hardware is now getting so cheap, that Window's license cost is really starting to show. This will only get worse. To stay competitive Microsoft will have to do two things. 1) Compete in the consumer marker with attractive devices (phones, tablets, Xbox, netbooks), and 2) Remain the "obvious" choice for business. In order to do #1 they either need to copy Apple and build premium devices by themselves or compete with Andriod/Chrome. Either way, their current OS revenue model of selling to OEMs is going to die. To do #2 they need to stay as ubiquitous as possible. You may not think that having a few MacBooks and iPads around the office matters to Microsoft but once they're there all of a sudden things like SharePoint and Lync and maybe even Exchange start to look less attractive because a big part of their appeal is built on how it all works together with Outlook and Windows. A few years ago quite a few Microsoft products had web interfaces that only rendered right in IE, they've had to stop that kind of thing more recently because non Windows devices are becoming more common - that trend is only getting worse. Open sourcing a Windows core and then selling server management tools and premium editions enables them to keep charging business while ensuring Windows stays relevant and as widely used as possible.