At CES next month, Microsoft will reportedly unveil a full-featured version of Windows that runs on ARM processors--a big departure from the x86 architecture.

Bloomberg, which broke the news this afternoon, reported that sources familiar with Microsoft's plans said this version of Windows will continue to work on x86 processors, but that it should improve battery performance on devices like tablets and other devices that use ARM processors.

Additional confirmation of Microsoft's plans came from The Wall Street Journal, which added that this new version will not be available for another two years. CNET heard similar reports from a source who added that Microsoft plans to detail this version of Windows at an invite-only press event several hours ahead of its CES keynote.

Microsoft declined to comment.

Rumors kicked up earlier this month about Microsoft previewing an early version of Windows 8 at the company's CES keynote speech, scheduled for January 5. The New York Times had also reported that Microsoft CEO Steve Ballmer would be demonstrating a Samsung-made iPad competitor with a slideout keyboard. Little else is known about the company's keynote plans.

Microsoft already has a version of Windows called CE that runs on ARM, however it's been designed for embedded systems. This version is also able to run on x86, Hitachi SuperH, and MIPS. Additionally, there's a version called Windows Embedded Compact 7 that's been built for tablets and other small devices. However, that does not quite match up feature-to-feature with a full-fledged version of the desktop OS, which this new version is said to do. Microsoft first introduced Windows EC7 as a public technology preview back in June.

ARM has remained the dominant architecture in small electronics devices like cell phones, both for its processing power and power efficiency--two things that have led to faster electronics with longer battery lives. PC makers like Dell have even dabbled with including ARM processors within PCs, as a way to provide instant-on capability for users who don't mind using Linux to do things like check e-mail or fire up a quick Web page versus doing a full boot into Windows. Much of this was in response to some of x86's shortcomings. Despite Intel pushing down things like power consumption, while boosting chip speed and the number of cores in product like the company's Atom chips, battery life did not see the same kind of massive gains.

But as far as its move to traditional personal computers, ARM has not gotten there quite yet. In the last year or so there has been a big movement in that direction with products like Apple's iPad, which utilizes an ARM processor and blurs the line between traditional computers and standalone entertainment devices--so much so that some of its features are headed to Apple's Mac OS. There's also Google's Android, which runs on ARM and is in the beginnings of making its move toward the tablet form factor. Worth a mention too is the nascent Chrome OS, which is largely being built to be CPU-agnostic.

Also, despite Microsoft's ambitions to get small and powerful tablets into the hands of users several years ago, projects have fizzled due to a combination of high prices, bulky designs, slow performance, and poor power consumption. This was especially true of a range of products dubbed the Ultramobile PC category, which ended up being the precursor to Netbooks (which now face problems of their own).

Will ARM be able to fix all these things and bring beefier versions of Windows into places it could not go before We should have a much clearer picture in about two weeks.

See also: Windows on ARM chips: Intel impact

Updated at 10:16 p.m. PDT with additional information about the timing of the announcement, and an additional source.