Microsoft has rolled out many new products and many revisions of old products over the past couple of decades. The releases haven't always gone well, as in the case of Windows Vista, but Redmond has managed to ride out the rough patches. However, Windows 8 is an even more dramatic revamp of one of Microsoft's top products than Vista was. At the same time, they're piling their tablet hopes onto Windows 8 as well. Does this make it Microsoft's riskiest bet ever? "Thus the problem facing Microsoft: How to convince Windows users to rush out and buy an upgrade of a perfectly good (and relatively new, at least by Windows standards) operating system? Compounding the issue is the new Windows 8 design, with a Start screen that discards the traditional desktop interface in favor of a bunch of colorful tiles linked to applications. That revamp is supposed to make Windows 8 more touch-screen friendly, and thus optimized for tablet use; but it could turn off consumers who don’t like change, not to mention businesses that shudder at the idea of retraining their workers in new ways of doing things. ... if Surface and the other Windows 8 tablets fail to make an impact on the market, then Microsoft will have lost a major chance at seizing the new paradigm, which is centered on mobility and the cloud. Meanwhile, that same paradigm shift is drifting the center of peoples’ computing lives from desktops and laptops to smartphones and tablets—which puts Windows’ traditional center of strength at long-term risk.