The first thing you’ll notice about Windows 8 is that it isn’t one operating system. It’s two. There are a couple different ways to do pretty much everything in Microsoft’s new OS. This sounds complicated, but it’s by design. Microsoft’s main goal in building Windows 8 was flexibility—the operating system is meant to run on traditional PCs, touchscreen tablets, and a new class of in-between “hybrid” devices (picture an iPad with a slide-out keyboard). To make all this possible, Microsoft shoved two different interfaces into Windows 8. For every computing task,...