Microsoft skips x64 emulation for Windows 10 on Arm

Previously lauded feature is going to be a Windows 11 exclusive.

Windows on Arm

With the progress Apple has made transitioning MacOS X and key apps to the Arm architecture (using Apple Silicon) one wonders what is holding Microsoft Windows back. One part of the problem is definitely the hardware situation – please read the previous article about Qualcomm’s plans for a sharper focus on this – but we also have the software problem, an area entirely within Microsoft’s scope of expertise.

Microsoft has some experience with writing OSes optimised for use on Arm processors. Many folk loved the Windows Phone OS, and still miss it as a mobile alternative to this day. However, Microsoft’s bigger Arm devices like its original Surface (AKA Surface RT, running Windows RT), and the newer Surface Pro X (running an Arm-based version of Windows 10), have hardly made a splash, even though they look like polished on both hardware and software fronts.

Last December, Microsoft blogged about the upcoming availability of x64 emulation in Windows 10 on Arm – so users can run modern 64-bit apps. The blog post has since been edited to reflect a new position the company is taking: “x64 emulation for Windows is now generally available in Windows 11,” Microsoft writes. “For those interested in experiencing this, a PC running Windows 11 on Arm is required.”

Windows insider Paul Thurrott’s radar blipped in the wake of the update, and he had a word with a Microsoft spokesperson about the matter, to make things entirely clear. The spokesperson more or less simply reiterated the blog edit statement – asserting that x64 is going to be Windows 11 only – but added the useful nugget that Windows 10 on Arm device users are guaranteed support until Oct 14, 2025 (but this is 32- not 64-bit support).

Being philosophical about the above news, until Qualcomm-Nuvia SoCs become available in 2023, Windows on Arm will remain a poor relation. If things live up to promises, we will see a big Intel-worrying change begin at around the same time.