JD88 :
Operating systems come already installed on store bought PCs, but the OEM still has to pay for them. OEMs are currently looking for ways to reduce costs and make hardware better in the race to the bottom that has occurred since tablets took over much of the market. For example, look at Chrome OS devices vs Windows devices in the same price bracket. They Chrome devices have about $50-100 worth of better hardware thanks to the OEM not having to budget so much for the now VERY overpriced Windows 8. Microsoft knows this which is why they are starting to offer Windows and Office free on lower end machines and tablets just to prop up their market share against Chromebooks and Tablets.
Linux has already won. There are more Android devices in this world than Windows devices and Chrome OS is catching fire. Microsoft is spending tens of millions on trying to bury it, but all they are doing is drawing attention to a competitor. The outdated business model of charging large sums for an operating system is simply not going to keep Microsoft floating in the long term and they know it, thus the transition to be more like Apple and Google. They have admitted as much.
Chrome OS devices don't have $50-100 better hardware because Chrome OS is a joke so it wouldn't be able to utilize it. There's really nothing else to say about it. Chrome OS might suit people who don't need to do anything taxing or professional, but I've seen more people with Surfaces than with Chrome devices [and I've only seen a handful of surfaces] And OEM's have always found other methods of subsidizing, like installing other services and AV. We hate it, but it makes the OS cost practically a wash for OEM's. That's something you can't do on Chrome OS, because it only supports the handful of things that Google allows on it.
Linux hasn't won crap. Android is a highly modified and comparatively limited system when talking about Linux. Almost all it shares with the Linux environment is its kernel. I'm referring to full OS's of the likes of Mac, Windows, Ubuntu, Mint, etc. That's why you had to broaden your statement with the term 'devices,' because on COMPUTERS, Android doesn't really exist, and Linux is not doing well at all. Only enterprise Linux distros you find on servers and supercomputers do particularly well in regards to marketshare.
And they're only giving RT away for free, not Windows 8, which makes sense considering RT is the biggest waste of time they've ever made and no one wants to touch it, and since it's almost as limited as Android and iOS and thus should be free.