In a new blog entry posted yesterday, Microsoft's (NASDAQ: MSFT) Steven Sinofsky, president of the Windows division, elaborated at length about Windows on ARM (WOA). He pointed out how WOA builds on the foundation of Windows, and that it has a "very high degree of commonality" and a significant shared code base with the x86/64 version of the Windows 8 operating system.

Reading through the post, it becomes apparent that ARM is no simple port of the x86/64 version of Windows 8. For a quick rundown on some of the most important differences, jump to our article.

Sinofsky offered a hint of the investments Microsoft has poured into WOA when he wrote: "Building WOA has been an ongoing engineering effort involving Microsoft, ARM licensees, PC makers, and developers of components and peripherals. These efforts spanned a wide array of subsystems that have been newly created or substantially re-architected for WOA."

In a bid to lengthen battery life, Sinofsky explained that WOA will not support traditional aspects of the Windows architecture such as background processes, system hooks and startup programs. Moreover, changes were also made to the registry and various components such as the handling of admin rights and unsigned drivers and add-ins, plus "a host of other common techniques."

It is evident that Microsoft is aggressively tweaking WOA to play well with mobility devices such as tablets, where the battery life is a major factor in purchasing decisions. And who won't want a computing device that can last for a full day away from a wall socket?

From another angle though, it doesn't take a huge leap of intuition to conclude that the underlying architecture of x86/64 Windows 8 is simply not ideal for long battery life. And if that's the case, then it would appear that the x86/64 of Windows 8 is really about creating a platform to which Microsoft's existing Windows users can easily migrate.

As more applications get written for WOA however, it is entirely plausible that WOA PCs, with their superior battery life, will eventually leave x86/64 Windows in the dust. - Paul Mah  (Twitter @paulmah)