The Start Button Returns—What It Means; Why It Matters

Microsoft desperately needed to bring to market a touch-centric OS designed for tablets. Rather than scale its recently released Windows Phone OS up, the company decided to adapt the core Windows product down. The result was Windows 8, a mobile and desktop OS merged into one, which has been both a success and a failure, depending on how you look at it.

Windows 8’s success stems from bringing Windows in line with new form factors, particularly with tablet/notebook hybrids that need...