By the end of next year, there could be nearly four times as many devices sold running on Google Android than on Microsoft Windows. That’s a staggering figure from research firm Gartner, which forecast device sales on Thursday. The company expects that of the 2.6 billion computers, tablets, and mobile phones sold in 2015, 1.3 billion of them will run Android. That’s half of the total market for next year and I think it’s a reasonable estimate. Android accounts for the bulk of mobile phone sales around the world these days and last year it topped iOS in the tablet market too. Combine that market clout with falling traditional PC sales and it’s easy to see why Gartner’s figures are solid. It’s also easy to see how the early ripples of computing change have become big waves of a shift that are crashing down on Microsoft.