Added note:

1) I'm on x86-64.

2) I downloaded it again, this time using "curl" from a Windows prompt. The filesize is different than when I did it from Firefox. (I renamed the firefox one to centos10s.wsl)

11/14/2025 05:22 PM 686,925,941 CentOS-Stream-Image-WSL-Base.x86_64-10-202510080808.wsl
11/14/2025 02:24 PM 1,263,831,040 centos10s.wsl

The new sha256 is: fa268e3f8246dc6412da676d27bed80c9dd34a041122e68a442f6262d0f37941

However, the same problem arises.

R:\centos>wsl --install --from-file CentOS-Stream-Image-WSL-Base.x86_64-10-202510080808.wsl --name CentOS10
Installing: CentOS-Stream-Image-WSL-Base.x86_64-10-202510080808.wsl
Distribution successfully installed. It can be launched via 'wsl.exe -d CentOS10'
Launching CentOS10...
Catastrophic failure
Error code: Wsl/Service/E_UNEXPECTED

Can you give a version for your WSL?

wsl --version

Microsoft Windows [Version 10.0.26100.7171]
(c) Microsoft Corporation. All rights reserved.

C:\Users\smujo>wsl --version
WSL version: 2.6.1.0
Kernel version: 6.6.87.2-1
WSLg version: 1.0.66
MSRDC version: 1.2.6353
Direct3D version: 1.611.1-81528511
DXCore version: 10.0.26100.1-240331-1435.ge-release
Windows version: 10.0.26100.7171

I also have a really old CPU, so if there are any things like AVX2 that are required for this, perhaps that's doing it?

It's an Intel i7-2700k.

Yep, that's a pretty old CPU. I'm betting that is the issue. CentOS Stream 10 raised the bar for what CPU's it would run on.

I'll see if I can double check the error, and if I can reproduce it (or others can) we'll put it in our documentation for the error you get for Unsupported CPU's.

Yep, that's a pretty old CPU. I'm betting that is the issue. CentOS Stream 10 raised the bar for what CPU's it would run on.

I'll see if I can double check the error, and if I can reproduce it (or others can) we'll put it in our documentation for the error you get for Unsupported CPU's.

Excellent. Not surprisingly to you then: CentOS 9 Stream did boot up, but with some minor "systemd" entry error. But I was able to get a shell at least.

I'll be checking in case there's an update from you as I'm still curious about it.