Unless there's a realistic alternative to Windows 7 that comes up (Linux isn't it, sorry)
Ah, if you hadn't said "realistic" I would have suggested ReactOS <g>.
ROS continues to be that option where businesses could have opted for a more sane MSWin alternative has they simply contributed some money, time and resources into advancing the project. But that would require many of these companies to NOT be cowardly little whiney-ass bitches.