Note: This story was originally published on June 15, 2012. It was republished on October 12, 2012 with additional details about Windows RT.
Coming off of our previous coverage, you may have heard about Windows 8 (read CNET's review) and Windows RT as being different. While Microsoft has made a point of available when compared with previous Windows releases, the company is also making a feature-limited Windows 8 version to run on ARM processors called Windows RT. Windows RT is more like Microsoft's attempt to do a Windows version of Apple's locked-down iOS than anything else.
What does "RT" stand for?
As with Windows NT, Microsoft has yet to clarify what "RT" actually means. Why on Earth Microsoft decided to name the ARM-powered version of Windows so ridiculously similar to the abbreviation for Windows Runtime, WinRT, is beyond the abilities of mere mortals to decipher.
Wait, what? Windows RT and WinRT aren't the same thing?
The short answer is, "Nope."
The long answer is, well, longer. Windows Runtime, also referred to as WinRT, runs on both standard Windows 8 and Windows RT. Runtime is the technical term for the engine that powers the new Metro apps. It's not the first Windows Runtime. "Runtime" refers to the collection of application programming interfaces (APIs) that allow developers to write software that can interact with the hardware and each other.
Windows RT is simply a name that Microsoft has given to Windows 8 on ARM. You wouldn't be entirely off base to think of it as "Windows Lite," given its restrictions and differences from standard Windows 8, which runs both Metro and Desktop modes.
What is Metro?
For one thing, , but it may be too late for that. Naming aside, Metro is the new user interface for Windows 8. Instead of icons, there are "tiles" that can surface information from the app in real time, and it's powered by WinRT.
So, what is WinRT?
Basically, WinRT is the underpinnings of the Metro side of Windows 8. But it does more than implement the Metro interface, it also simplifies much of the programming for Windows developers. Coding for Metro is significantly easier than writing a program for Windows 7 and earlier. This is important for Microsoft because it can now point to Windows 8 as an attractive place for developers to ply their trade.
What's the difference between Windows 8 and Windows RT?
- Windows RT will work only on ARM-powered devices
- Windows RT will have a Desktop mode, but it will be restricted to pre-installed, Microsoft-produced software. This will include touch-optimized versions of Microsoft Word, Excel, PowerPoint, and OneNote as the
- Windows RT will come with device encryption
- Neither old nor new x86/x64 programs will work on Windows RT
What devices will run Windows RT?
Manufacturers are being extremely cautious about embracing Windows RT. Of all the changes in Windows 8, the biggest unknown is predicting how people will react to its "Windows 8 Lite" approach. Here's , but we've pulled out the Windows RT devices below:
- Microsoft Surface RT: Microsoft is making a big splash with its first in-house designed computer hardware ever. There will be two versions of the Surface available, one running Windows RT and the other running standard Windows 8. You can buy the Windows RT version, called Surface RT, when the operating system and hardware from Microsoft's manufacturing partners is made available to the general public on October 26.
- Dell XPS 10 Tablet hybrid: A of the XPS 12, which will be running full-fledged Windows 8. The unique design is resurrected and renamed from the line.
- : Like the XPS 10, the IdeaPad Yoga comes in two sizes. The smaller one will run Windows RT, while the larger gets full-fledged Windows 8. Also like the XPS 10, the Yoga brand features a unique design where the screen can bend back on itself. No word from Lenovo on whether it will help you with your Sun Salutation.
- : Samsung's no stranger to tablets, thanks to Android. Ativ Tab is the most Android-looking of the Windows RT hardware that's been announced so far.
What kind of apps can Windows RT run?
The focus of Metro apps will be on Internet connectivity, cloud synchronization, and responsiveness. If it works in Windows 8 Metro and does not open in Desktop mode, it will work on Windows RT.
Will I be able to update an old ARM-powered device with Windows RT?
No. At this point, Windows RT will be available only pre-installed. That's not expected to change, either.
What's the benefit of ARM?
ARM processors power virtually all iOS, Android, and other mobile devices on the market. ARM has gained so much traction in large part because of its better battery management. Malware designed to run on current Windows computers generally won't work on ARM's chips. ARM could be a huge boon to Windows, if only Microsoft can convince people that Windows RT is worthwhile.
Are there any other drawbacks to Windows RT?
There are a couple that stand out so far that we haven't mentioned yet.
- There are certain core APIs that Microsoft is restricting access to in Windows RT that are available in full Windows 8. This has caused and has raised fears that Microsoft is attempting to cut off browser innovation by locking down Windows RT the way Apple has locked down iOS.
- The OEM , so it's likely that Windows RT devices will be notably more expensive than their Android-powered counterparts.
- While we've seen some hardware specs for standard Windows 8 devices, including tablets, we haven't seen any confirmed specs for a single Windows RT tablet. That doesn't bode well for manufacturer confidence.
- There doesn't seem to be a way to visually distinguish a Windows RT tablet from a Windows 8 tablet, which could lead to buyer confusion, to put it mildly.
Windows RT remains the biggest gamble that Microsoft is taking with Windows 8, because it's cutting itself off from legacy Windows. Sure, there's a free version of Office included, and that may draw some people in on its own. There's scant evidence from consumers or manufacturers that they're interested in this version of Windows 8, but it could also position Microsoft for future growth in a way that limiting itself to Intel chips can't.
Correction, Friday, June 15, 2012, at 11:50 p.m. PDT: The original version of this FAQ conflated the terms "Windows RT" and "WinRT." They have since been clarified.