Parallels WIndows 11 ISO can be used to install a VM on Fusion 13

[Technogeezer]

I ran a little experiment after seeing what Microsoft and Parallels announced this week.

I installed the trial version of Parallels Desktop 18 as I was curious what build of Windows 11 they were using. After installation I proceeded to have it install a Windows 11 VM. The first thing that it did was to download a Windows 11 ARM installation ISO file named:

22621.525.220925-0207.ni_release_svc_refresh_CLIENTCONSUMER_RET_A64FRE_en-us.iso

Parallels tech notes say that they are downloading the file "from Microsoft". So I asked myself: "Self, I wonder if this ISO will work with Fusion?"

The answer:  Yes it does. The ISO appears to be a pretty vanilla version of Windows 11 22H2 (build 22621.525). I skipped the procedures in the Companion Guide for building an ISO from uupdump.net and jumped straight to the procedure to create a VM and install from ISO. No issues with the ISO and no changes to the procedures in the Companion Guide. So far the VM is behaving fine and updating itself to the 2023-02 Cumulative Update for Windows 11 for arm64-based Systems.

So, if you have this Windows 11 ARM ISO that Parallels downloaded for you, the installation of a Fusion Windows 11 ARM VM just got a little easier. 

So who blinks first? Microsoft to release publicly the ISO for Windows 11 ARM, or VMware to provide a similar ISO for download like Parallels does?

[ColoradoMarmot]

I'm so tempted to put a sniffer on the network and find the URL they're using....

[gringley]

When I tried Parallels last year they downloaded a non-bootable ISO and then inserted a WIM boot loader - that did not work with Fusion.  This implies that Microsoft has perhaps made a VM bootable ISO now?  

[Technogeezer]

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@gringley wrote:

When I tried Parallels last year they downloaded a non-bootable ISO and then inserted a WIM boot loader - that did not work with Fusion.  This implies that Microsoft has perhaps made a VM bootable ISO now?  

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Can’t say for sure but it looks like something has changed. The file name sure looks like something only Microsoft would come up with - nobody else would take the time to put that much detail into an ISO file name. 

If only some enterprising soul could reverse engineer where this file resides…

[pruthe]

I also acquired the Windows 11 arm iso and followed the required companion guide installation steps. It worked!!! Checking out Windows 11 now on Fusion 13.

Thanks for the info!

[bogdam]

It doesn’t download the ISO, it downloads the ESD and converts it to ISO. 

ESD to ISO on macOS https://gist.github.com/b0gdanw/e36ea84828dbd19e03eff6158f1fc77c

[Technogeezer]

@bogdam I think you have found the magic incantation I was looking for to find the Microsoft ISO. If things pan out this will make life easier for us. I'll give this a whirl and see what my experiences are.

Fingers crossed. Thanks!

[Technogeezer]

Hey everyone! I think I have a breakthrough.

Given the information the @bogdam posted (the link was very helpful)  - I have reversed engineer the process that Parallels is using to get a Windows 11 ARM ISO directly from Microsoft (well, they don't get the ISO from Microsoft, but they are getting the ESD and using open source and macOS tools to create the ISO). I did not feel comfortable extracting stuff from the Parallels ISO, so I went down the reverse engineering path to see exactly what they were doing.

What they're doing is not rocket science. The reverse-engineered process uses the utilities in the open source package wimlib-imagex, and the macOS command hdiutil.

I'm going through final testing right now, but the initial tests have the ISO booting entering Windows Setup. It's installing files to the hard drive right now, and in about an hour or so I should have a working VM.

If this works out, I'm set to remove all references to uupdump from the Companion guide in favor of this process. 

Keep your fingers crossed!

[gringley]

OK so Parallels is still building the ISO on your Mac.  Wonder what would have changed to make it bootable in Fusion though?  I would expect Parallels to insert a boot loader for their virtual hardware and thus was not surprised when the ISO did not boot elsewhere.

[Technogeezer]

@gringley From what I'm seeing in reverse engineering the process, Parallels appears to be taking the bits for the arm64 boot loader that Microsoft provides in the ESD. The Parallels installation process is injecting something in the install, though, since there are a lot of questions in the Parallels installation from ISO that are being answered for you. Similar to what Fusion does for its easy install where supported.

I'm still not finding anywhere that Microsoft is providing a ISO, but having an ESD is big step forward. And Parallels' note that they are getting Windows "from Microsoft", while technically true, isn't exactly the same as getting an ISO from Microsoft. although all the same bits are there. 

The ISO build process from a downloaded ESD from Microsoft is actually relatively quick compared to  building from uupdump.net. And it works on the Mac with only one open-source package download.

I have a prototype script that automates the build process. I'd appreciate some kind souls to test it out before I include it as part of the Companion. Or I can post a manual procedure - but that's complicated if your system language is not US English as you have to go to Microsoft to find the files for the download. The script makes that really easy.

[bogdam]

My post keeps getting deleted, so .... nevermind

[Technogeezer]

@bogdam . Interesting post, and interesting that they consider what Parallels did "amateurish". But one of the issues is that the tools the poster referenced only work on Windows . For Mac users wanting to iinstall Windows, that's kind of a Catch-22 - you need Windows for the tool that will let you install Windows. So I guess Parallels had to do what they did to get something that worked on macOS without the need to go back to a Windows system. To be honest, what they did just looks like productizing what's available in open source utilities - but I have to give them credit for making it look easy. 

I'm also noting that what the posts are pointing to are MSDN releases. During the Tech Preview process, a VMware employee posted that he was able to get Windows 11 ARM working from an MSDN release, so this is not a totally new revelation. But most people that are Windows 11 ARM users on Parallels or Fusion aren't likely to have MSDN subscriptions.

I've put the finishing touches on a script that implements the reverse-engineered process to create the ISO from ESD. It's working pretty reliably right now and should make the process accessible to less technical users. And it even knows how to get languages other than en-us (I've put a secret decoder ring to language/region tags in an upcoming release of the Companion Guide). A hearty thanks to you to point me to the GitHub post from which I was able to put this all together.

Now I'm just looking for volunteers to test out my script more widely before releasing it to the public. PM me if you're interested.

[gringley]

I am realizing that this is probably what Parallels was doing last fall too, I was just not digging deep enough to see they were downloading an ESD and not an ISO.  As a MPSA holder I have been able to get the regularly updated (21H2 and 22H2) Windows 10 and 11 ARM ISOs most recently updated last week for Feb 2023.  No idea where a consumer user would get something like that though?

[Technogeezer]

You're spot on. Us mere mortals don't have access to those MSDN/MPSA releases. That's why Parallels built their utility. I just replicated what they're doing based on what I was observing and what @bogdam posted.

[PenguinBelly]

nm

[conkotronis]

I'm interested in testing your script out

[Technogeezer]

@conkotronis check your private messages.

[kymatica888]

can i use your script? im having the worst luck simply trying to run windows 11 on my macbook m1. the reason i bought vmware fusion to being with.

[Technogeezer]

Check the Unofficial Companion Guide https://communities.vmware.com/t5/VMware-Fusion-Documents/The-Unofficial-Fusion-13-for-Apple-Silicon.... It has the link to the script and instructions on how to use it.