Microsoft: ARM-Based Devices Won't Run Windows 7 x86 Apps


The transition from Windows 7 to Windows 8 might not be so seamless after all.

Windows 7 applications written for x86 PCs won't run natively on Windows 8 on ARM-based devices, a Microsoft executive told financial analysts last week. Developers will have to port their Windows 7 software to the ARM architecture.

Speaking at Microsoft's Build conference last Tuesday, Steven Sinofsky, president of the Windows and Windows Live Division, said that everything that runs on Windows 7 would run on Windows 8. Microsoft has worked hard to avoid the kind of application and third-party device compatibility problems that plagued Windows Vista.

But Sinofsky, speaking at a financial analyst meeting one day later, clarified his comments to say that ARM-based systems won't run Windows 7 applications developed for x86 PCs without modification.

An analyst asked Sinofsky about his comments that "legacy applications will be able to run on Windows 8 regardless of the chipsets that people are choosing," according to a transcript of the analyst meeting Q&A session posted on Microsoft's investor relations Web site. The analyst asked whether some kind of software emulation or application virtualization would be needed.

"I don't think I said quite that," Sinofsky said in response. "I think I said that if it runs on a Windows 7 PC, it'll run on Windows 8. So, all the Windows 7 PCs are x86 or 64-bit.

"We've been very clear since the very first [Consumer Electronics Show] demos and forward that the ARM product won't run any X86 applications," he said. "We've done a bunch of work to enable that – enable a great experience there, particularly around devices and device drivers. We built a great deal of what we call class drivers, with the ability to run all sorts of printers and peripherals out of the box with the ARM version.

"What we talked about yesterday was – what we announced yesterday for the first time was that when you write a Metro style application, all the tools are there to enable you in any of the languages that we support to automatically support ARM or x86. I think that's the key part of everything that we'll run," he said.

"Metro" is Microsoft's name for the typography-based design language the company created for its Windows Phone 7 mobile operating system and is using for developing the Windows 8 user interface for both x86- and ARM-based devices.

Unless Windows 7 applications are re-ported to the ARM architecture, Sinofsky said, they won't be able to take full advantage of its capabilities such as low power consumption.