Bridging the Gap, the Dichotomy of Windows RT

by Anand Shimpi

I described Windows RT as being a tablet OS with all of the underlying Windows-ness of Windows. You can get the big full screen app experience in tablet mode, but poke around your file system with Explorer or use Office 2013 like you would on a traditional notebook if you want to. If the two sides of Windows RT remained fairly separate that’d be one thing, unfortunately there are some dependencies between the two sides of the OS that keep the overall user experience from being as friendly as it is in iOS. There are still occasional reminders that you’re dealing with something that’s distinctly Windows here.

Most mobile OSes have done their best to hide the underlying file system and shell from the end user. Microsoft did, in my opinion, the smart thing and avoided hiding its roots with Windows RT. Although the new Start Screen is the default UI for Windows RT, there’s a big desktop tile front and center that will take you back to something far more familiar:

Unlike the Windows 8 desktop, you’re pretty limited in what you can do here. The only applications that are allowed to run in desktop mode under Windows RT are Explorer, IE10, Office 2013 and the command prompt (there are also all of the Windows specific tools and settings which I’ll get to shortly). Developers cannot make applications for Windows RT desktop mode and you can’t sideload anything here. Microsoft’s belief is that by completely locking down the system, requiring that applications only come from the Windows Store, it can avoid the pitfalls of viruses and malware that can plague Windows machines today. 

Steve Sinofsky famously quoted an analyst when they asked if Windows RT would be backwards compatible with all of the legacy Windows viruses and spyware. The answer was an astounding no, and this is exactly why we can’t have open season on Windows RT desktop development. There’s also the obvious financial angle to all of this. Microsoft takes a cut of any apps sold through the Windows Store.

Coming from the perspective of a traditional Windows user, the lack of flexibility on the desktop seems wrong. From the perspective of the rest of the ARM  based tablet space, it’s not a big deal. At least Windows RT gives you direct, first party access to the file system. There’s very little exposed through iOS, and with Android you need to download a third party app to get access to the file system.

Explorer works just as it would on a Windows 8 PC. The folder structure is exactly as you would expect it on any Windows machine. There are even some x86 remnants in the Windows RT install such as a C:\Windows\SysWOW64 directory complete with x86 binaries inside that obviously won’t run on your Windows RT tablet. 

Internet Explorer in desktop mode works just like a traditional IE windows application would work. The desktop app actually controls settings and features for the Metro...err...fancy IE10. For example, if you want to change security settings, clear your history or empty your cache, you have to do all of these things from the IE10 desktop application. Fancy IE10 doesn’t expose them. 

The command prompt is, well, a command prompt. It features all of the same commands that you could run before, although once again you can’t simply drop an x86 exe on your system and run it. Not having binary compatibility can be frustrating at times. 

Although developers can’t build applications for Windows RT’s desktop, you can write and execute batch files. Keep in mind that if your batch file needs any additional support files (e.g. sleep.exe) you’ll need ARM versions of them which, unless they come from Microsoft, just isn’t happening.

As I mentioned earlier, there are a few other things you can run and do in RT’s desktop mode. Control Panel, event viewer, disk management and all of the other administrative tools that you’d expect to come with Windows are present in Windows RT (including regedit). There are also the little apps that Microsoft has always included, which also work in desktop mode (e.g. mspaint, calc, notepad, etc...)

Ultimately Windows RT is an ARM version of Windows with tablet makeup on. You still get all of the normal bits and pieces of Windows, minus some flexibility and of course, backwards compatibility.

For years we’ve been asking Microsoft to make a clean break with its legacy code and introduce a version of Windows that was built from scratch, with only support for the latest hardware. With Windows RT, Microsoft finally delivered some of that, but in a sort of weird, backwards way.

As Windows RT only supports the ARMv7 instruction set architecture, none of your old x86 applications will run on the platform. Microsoft hoped to avoid this being a problem by shipping an ARM version of Office 2013 Home & Student Edition with Windows RT tablets, and by directing users at the Windows Store for the rest of their application needs. Although it would’ve been possible for Microsoft to enable x86 compatibility through emulation or binary translation, performance would’ve likely been pretty bad.

The loss of backwards compatibility with years of Windows applications feels wrong, but from Microsoft's perspective you don't get that with iOS and Android so there's no real competitive disadvantage here. Why bother with an ARM based version of Windows to begin with? To bring competition to Intel and ensure that it will be able to deliver Windows to the new wave of ultra mobile devices (e.g. tablets). Intel hasn't been competitive on power or pricing at the low end (read: Atom) of the spectrum for years now. The introduction of Windows RT changed that. Atom Z2760 (Clovertrail) is around half the price of the cheapest Atom CPU of the past five years, and it's price competitive with solutions from Qualcomm. We have Windows RT to thank for that. Without pressure from ARM, Clovertrail would've started around $50 per chip just like Intel's low end parts had in the past. As AMD is no longer a pricing check for Intel in some of these new markets, Microsoft had to look for a new way to offer balance. Supporting ARM is its way of doing that. Until there's a new pricing/power/performance x86 competitor to Intel in tablets, ARM and Windows RT will remain.

User Interface, Gestures, and Multitasking First Party Applications: Mail, Calendar, Messaging and Bing
Comments Locked


View All Comments

  • Dorek - Friday, November 2, 2012 - link

    AFAIK, task manager tray doesn't even have thumbnails. Come on, it's not comparable to what Windows 8 and Windows RT do. Have you used them?
  • yyrkoon - Sunday, October 28, 2012 - link

    The software issue, will not be much of an issue at all.

    Microsoft will just write another abstraction layer ( HAL ) for ARM. Which is most likely what they've done here.

    Passed that. IF any abstraction layers need to be written for the COM model, or .NET libraries. You can rest assured Microsoft will cover that as well. If it hasnt been covered already. Which Im betting it has.

    Again, this is nothing like WinCE.This is a real OS, for real end users, with a different HAL.

    The biggest issue as I've stated in previous posts. Is not whether it will be easy to write applications for Windows RT. But whether software developers deem it prudent to spend thousands of dollars on Microsoft development tools( not absolutely necessary ). THEN pay Microsoft a forced 30% distribution fee. Through their app store.

    For me personally. The 30% fee alone is enough for me to jump ship. And I really enjoy writing apps for Windows. We'll see how it all works out in the end.
  • karocage - Friday, October 26, 2012 - link

    This comment from the article seemed odd to me:

    "This isn’t like Windows Phone, where we need to see whether the platform will get any market traction before predicting the growth of the app marketplace."

    Market traction and app store growth don't seem to have much if any relationship with Windows Phone. WP7 hit 100,000 apps faster than either iOS or Android and has over 125,000 now. If anything, that would seem to indicate that MS really does have a lot of pull with developers independently of market share. So while I agree that the sheer number of devices will be a big draw, I'd argue that's just the cherry on top that guarantees we're going to see a ton of support really quickly for RT/Metro apps.

    Obviously buying a WinRT tablet today will be pretty limiting in terms of 3rd party software, but experience from WP7 suggests this will be a very short-lived downside of the platform.
  • Dorek - Friday, November 2, 2012 - link

    Good point. I've been on Windows Phone 7.5 for a year, and have never had the problem of not being able to find an app I want. (With the exception of Pandora, the assholes. Can't even use third-party ones because they block them. But I have a Zune--I mean, Xbox Music Pass anyway. So screw Pandora.)
  • andypost - Friday, October 26, 2012 - link

    Anandtech writes the best articles. period.
    Thanks to Vivek Gowri and Anand Lal Shimpi for a great article.
  • Visual - Friday, October 26, 2012 - link

    You say it is impossible to make desktop apps, but...
    I read that Win RT still has PowerShell. A lot of PowerShell scripts on x86 just invoke various functions in third-party ActiveX controls, which are just x86 executable binary libraries, and that will not work on RT... but maybe at least the core MS objects still work? For example, if Windows Forms or Windows Presentation Foundation still works, then PowerShell scripts can create desktop windows with various GUI elements.
    And since there is an IE, maybe HTA applications work as well?
    Do you have some scripting geek working at AT that could test these theories out?

    On another topic, I am very surprised you say there are x86 executables on your install. That is just wasted space on a device that doesn't get a large drive to begin with anyway. MS would get in serious trouble if it were true... Are you sure?

    And lastly, I am curious if a Win RT device is supposed to be able to get plugged to a "real" Windows computer over USB for charging or for as a mass storage drive, for transfering files... If it is, then coudn't you also plug one RT device to another RT device? Then which one will become the "host", and which one will become the peripheral?
  • Dorek - Friday, November 2, 2012 - link

    "And lastly, I am curious if a Win RT device is supposed to be able to get plugged to a "real" Windows computer over USB for charging or for as a mass storage drive, for transfering files... If it is, then coudn't you also plug one RT device to another RT device? Then which one will become the "host", and which one will become the peripheral?"

    Dude...that's deep.

    (That's actually a really good question. Surface can't be charged over USB, but I don't know about other ARM devices.)
  • tommo123 - Friday, October 26, 2012 - link

    i mean if someone writes an app and gives it away. there's no sideloading so if has to go through the store right?

    will microsoft host it for free? if not then they're effectively killing off free software for windows are they not? at least win rt which is eventually (how they'd like) desktop windows to go too.
  • tipoo - Friday, October 26, 2012 - link

    Yes they'll host it for free. And there are many free apps already, there was a influx of apps on launch day and most reviews were done before that. They only take a percentage of the cuts from paid apps, nothing from free.
  • Visual - Friday, October 26, 2012 - link

    I forgot one question in my previous post.
    How is the browser performance with many many tabs open at once? Like 20, or even 100?
    I sometimes use tabs in a bit weird way, ctrl+clicking possibly interesting links in some large index page to open them in a background tab for later reviewing it in more detail. Even without Flash, with IE9 starting a new process for each tab by default and a few animated gif ads and various JS scripts on each tab, it really kills Atom Netbooks and even CULV Core 2. It's probably more of a memory usage thing than a CPU thing actually... But anyway, how could that go on these new ARM devices?

Log in

Don't have an account? Sign up now