[caption id="attachment_17339" align="aligncenter" width="567"] Windows 8's tile-based Start screen.[/caption] Microsoft has sold 200 million copies of Windows 8, roughly 15 months after the operating system’s release. According to The Verge, Microsoft executive Tami Reller told the audience at a Goldman Sachs technology conference this week that the number of Windows 8 licenses sold is “stunning.” Except that’s not really true: it took Windows 7 a mere 12 months to blast past 240 million licenses sold, which means Windows 8 lags its predecessor on the all-important sales front. Windows 8 faces several uphill battles in its quest for adoption. First, anemic PC sales have suppressed the need for new desktop-and-laptop operating systems, harming Windows on that front. Second, Google Android and Apple iOS are deeply entrenched among mobile-device users, making it difficult for Windows 8 (which was designed for tablet as well as PC use) to gain any sort of toehold there. Third, consumers haven’t really taken to Windows 8’s user interface, which conjoins the traditional desktop with a touch-friendly Start screen composed of colorful tiles linked to applications. The Next Web features an interesting graph of Windows 7 and Windows 8 adoption over the operating systems’ respective lifetimes. Both platforms enjoyed roughly parallel uptake during their first six months, suggesting an equal number of presales to OEMs and corporations; after that, however, Windows 7 accelerates ahead while Windows 8 rises at a slower rate. Released in late 2009, Windows 7 enjoyed pent-up demand from Windows users who’d skipped the much-maligned Vista. But Windows 8 didn’t hit the market with any sort of tailwind: Windows 7 users generally seemed happy, most businesses take quite some time to upgrade to new operating systems, and more people have made their smartphones the center of their computing lives. No wonder Microsoft reportedly has Windows 9 underway. According to Paul Thurrott’s Supersite for Windows, the company will begin discussing the next version of the operating system (codenamed “Threshold”) at April’s BUILD conference. “Threshold is more important than any specific updates,” he wrote. “Windows 8 is tanking harder than Microsoft is comfortable discussing in public, and the latest release, Windows 8.1, which is a substantial and free upgrade with major improvements over the original release, is in use on less than 25 million PCs at the moment.” Thurrott also indicated that Microsoft would likely tweak—but not abandon—the tile-based interface that’s met with so much criticism from users. If that proves the case, how will Microsoft convince users they need to upgrade?   Image: Microsoft