It didn't happen overnight but the BYOD (bring your own device) trend that developed with the arrival of sophisticated non-Windows tablets like the iPad and smartphones like the iPhone and Android phones, has in many ways hijacked enterprise IT. It has put the power of device choice in the hands of employees.

It doesn't help Microsoft that the iPad is being deployed at many enterprises due to user demand and that the PC-only OS Windows 7 is well-liked by businesses and consumers who are in no rush to upgrade to Windows 8.

"Windows 7 is the OS of choice for enterprises right now, and most are in the middle of their transition from XP to 7 and not ready to invest in another migration," says David Johnson, senior analyst at Forrester Research. "Our data show enterprise IT interest in Windows 8 at half the level that it was for Windows 7 at release."

No Windows Vista to Spur Demand

The arrival of Windows 7 in Oct. 2009 came under much different circumstances; it was the follow-up to the scorned Windows Vista, so there was pent-up demand for Windows 7 in the enterprise. In addition, when Windows 7 came into the world, there was no iPad and smartphones were not as sophisticated as they are now (Android was in its infancy in 2009). Windows 7 was not competing with an assortment of touch devices, but Windows 8 is.