Windows 10 S is a bold move by a Microsoft that recognises the threats iOS and Chrome OS present to its Windows monopoly. This isn't the first time Microsoft has attempted to move Windows into a position to compete with new paradigm operating systems - that was Windows RT - but this is the first time that it can actually pull it off.
When RT launched alongside the original Surface and Windows 8 it slammed straight into controversies left right and centre. Windows 8 was an OS designed to work in both desktop and tablet modes in order to be ready for a new post-PC generation which was expected to focus around tablets, in the wake of the intial success of the iPad. Very few people understood or liked it. RT had the same split personality, with the added restriction of only being able to run apps which had been re-compiled for ARM processors.
Windows 10 S is different. Everybody loves Windows 10 - 400 million users can't be wrong. The new platform's success has gone hand in hand with Microsoft's success as a hardware manufacturer, with a run of success going back to the Surface 3 and Pro 3.
Windows 10 S is being presented as a platform for education, however there's a certain inevitability about it finding its way onto consumer laptops, likely with the same $49 upgrade offer. With Microsoft betting most of its customers won't bother.
By promising better security, better performance and greater longevity from machines sporting Windows 10 S Microsoft is offering a value proposition which will be attractive to many customers - one which levels the playing field with Apple and Google. The trade off? Windows Store apps only. A trade off that many customers will be happy to make.
For Microsoft the more users it has on Windows 10 S the more leverage it has with software publishers, who it needs to persuade to support the Windows Store to make the whole thing hang together.
It's a plan designed to battle a future where Apple and Google have made Microsoft and Windows as irrelevant on the desktop as it is on the smartphone. For Google and Apple it becomes an interesting challenge. With Chrome and iTunes unavailable on Windows 10 S (for now anyway) if the new platform is a success that's a whole chunk of users they can't access. If they decide to convert to the Windows Store they validate Windows 10 S for Microsoft.
Whether this will become Windows RT revisited or further enhance Microsoft's record of success remains to be seen.