Microsoft Released the Windows 11 on Arm ISO, and I Have Some Advice

Almost six months after PC makers delivered the first Copilot+ PCs, Microsoft made Windows 11 on Arm available for download. But there are caveats. Aren’t there always?

If you’re familiar with this on the x64 versions of Windows 11, you know there’s a Download Windows 11 page on Microsoft.com that provides three ways to download and install the OS. You can get a Windows 11 Installation Assistant, which is the lengthiest but most reliable way to upgrade to the latest Windows 11 version. There’s a Windows 11 Media Creation Tool that can be used to download the Windows 11 ISO (disk image file) and then optionally create installation media on a USB flash drive (or, amazingly, a DVD disc). And then there’s a direct ISO download.

But Microsoft has never offered anything like that for Windows 11 on Arm (or, for that matter, its predecessor, Windows 10 on Arm). If you were lucky, your PC maker provided a downloadable recovery image, but to know understanding, most did not. So if you found yourself with a non-bootable or otherwise non-working PC, you had to go through your PC maker’s support channels and hope for the best.

The other issue, of course, is that those who put Windows 11 on Arm PCs in the Windows Insider Program could find themselves at the end of a one-way, dead-end street. The way this system is designed to work, you can configure your PC to un-enroll from whatever Windows Insider channel you’re in when that version of Windows 11 reaches stable. But because these channels don’t always map to a specific version, and don’t usually offer channel hopping, that milestone was never reached. So the only option was to use Reset this PC, try the cloud download option, and, again, hope for the best.

What was needed all along was the same options that Microsoft has always provided for Windows 11 (and previous versions) on x64: A way to get the official, stable, and current version of the OS in some downloadable and installable form. At the very least, an ISO.

And now Microsoft has finally done the least it should do. Seven years after the initial release of Windows 10 on Arm, three years after the initial release of Windows 11 on Arm, and six months after the initial release of Windows 11 on Arm version 24H2, it has given the world a single ISO download.

Hooray.

But as noted, there are caveats. And I have some advice. Please pay attention to this.

First, understand what’s missing. There’s no Windows 11 on Arm Installation Assistant, for example, and no Windows 11 on Arm Media Creation Tool. All you can do is download the ISO file manually and then figure out how to turn that into a bootable USB flash drive on your own. I’m working on that now.

But whatever the need, this ISO should be the last-ditch option for anyone who owns a Windows 11 on Arm-based Copilot+ PC. That is, you should avail yourself of every recovery and OS install option available on that PC before you even try to use that thing. You should create a recovery drive as I document in the Windows 11 Field Guide.  You should try Reset this PC. If you’re only trying to fix issues and not reset the entire PC, you should try the new Reinstall Windows with Windows Update functionality in 24H2.

But most importantly, if your PC maker supports it, you should download the OS recovery image for your exact PC and recreate—and then use—that recovery disk first. The issue is that not all PC makers offer such a thing, so you’ll need to check. One PC maker that does offer this is Microsoft: You can download recovery images for Surface Pro 11 and Surface Laptop 7 from the Microsoft website. And you should. You should ignore this new ISO download and use that instead.

Why?

Because this new ISO download is lacking in two key ways.

First, it does not include the 20+ small language models (SLMs) that PC makers are required to bundled on their Copilot+ PCs. So a clean install with this ISO, even when successful, will require you to manually download one or more SLMs each time you trigger a Copilot+ PC feature.

That’s a minor inconvenience. But this one is more serious. As documented on the Microsoft Learn website, “depending on the [PC], it will likely be necessary to include drivers from the device manufacturer for the installation media to be successfully bootable.” Worse, while Snapdragon X-based PCs will boot using the drivers on the ISO, they won’t work properly until you install other drivers that are not included with the ISO. Like networking drivers needed to get online. Which is how you get all the other drivers in the first place.

Here’s Microsoft’s workaround for this, which is familiar because I go through this a lot with x64-based PCs, too.

“[PCs] with a Snapdragon X Series processor will not have full functionality until the remaining drivers are installed. To install those drivers and restore functionality, use an Ethernet connection via dongle or dock to connect to Windows Update to download the drivers. Once drivers are installed and the device is rebooted, all subsystems in the device will be functional.”

If you have an older Windows 11 on Arm PC, you’re on your own. For those PCs to work at all with this ISO, the ISO must be updated with drivers from the PC makers “injected in the image.” Good luck with that.

There is one place this ISO can be used without reservation: In virtual machines. This can be Hyper-V on Windows 11 on Arm, of course, but also Parallels on the Mac. If you’re using Parallels and Windows 11 on Arm is stuck on 22H2 or 23H2, you can use this ISO to upgrade it and take advantage of the performance advantages of its new Prism emulator. So that’s good news, at least. The way I did this previously, via a UUP dump download, is not advisable for most people.

Anyway, we finally got the ISO. God help us all.