Win11 24H2 install fails consistently

olivierlambert

Adding @dinhngtu in the convo

markr

Win11 24H2 business editions iso fails with C000021A instead, which is a winlogon crash. My guess is that something else is going on that is destabilizing winpe or whatever they are using these days to run the install.

dinhngtu

@markr I did a test install with en-us_windows_11_business_editions_version_24h2_updated_july_2025_x64_dvd_d32522f0.iso which went to OOBE with no issues. If you have a new Intel CPU, does doing https://docs.xcp-ng.org/troubleshooting/windows-pv-tools/#windows-bug-check-0x3b-system_service_exception-on-systems-with-newer-intel-cpus help?

markr

@dinhngtu as this is my homelab, I only have old stuff, intel, but old.

Now I'm curious what hw platform specific nonsense they are doing that breaks things. Install works up to 23H2, then it doesn't.

Greg_E

@markr

How old is old? I had some problems with server 2022 a few years ago on old Xeon x5660 processors, wonder if 24h2 is failing on old things like Xeon v2.

Andrew

@markr @Greg_E I just installed a fresh copy of retail Win11 Pro 24H2 from ISO and all updates on my XCP 8.3 host with Xeon E5v2 CPU. Win11 installed and I get to the desktop to install the Xen tools. I have Secure-Boot, TPM, and driver update enabled in the settings.

Greg_E

@Andrew

I haven't had my E5 v2 system up for several months, but it was working with Win11 24H2 back when it came out. That was on XCP-ng 8.3 before LTS, not sure if there would be a difference in the host OS. It should be working.

Did you use EFI or BIOS mode when you made the VM, all my testing was with EFI mode since win11 really prefers EFI. Shouldn't matter but worth looking at.

Also I was using the evaluation versions, Pro and LTSC, which again shouldn't be an issue but maybe.

https://www.microsoft.com/en-us/evalcenter/

Somewhat concerning since server 2025 uses the same core as Win11, normally what buggers one buggers the other.

Also, I didn't see which set of tools you are running, Xen 9.4.1 or the XCP-ng tools? Could be another variable, if you were using the Xen 9.4.x, it might be interesting to try going back to 9.3.3 if you had them. I know there is a security issue, but worth trying to see if older works.

dinhngtu

If the host is really old I'd also check Windows 11 version 24H2 supported Intel processors

markr

@dinhngtu yeah it is a Intel(R) Core(TM) i5-4250U and it definitely is not supported. My production pool is three newer nucs that are supported, but they are currently not running xcp 8.3.

The odd thing is that win11 works on this host up to 23H2 and then it doesn't.

markr

@Greg_E for the upgrade, the vm has the citrix drivers installed. For a new install, it never got that far. Anyway, it appears to be that the host cpu is too old.

Greg_E

@markr

I'm not certain on the CPU age here, but maybe. If you set up on a newer host with the same OS and everything works, then yes the CPU could be declared as too old.

XCP-ng-JustGreat

@markr All, I am currently running Windows 11 24H2 on an Intel Haswell i7-4700HQ laptop and it runs fine. What's more, it was in-place upgraded from Windows 11 23H2 using the (still working) setup.exe /product server switch compatibility bypass. (Simpler than all the LabConfig registry tweaks.) The only change I know of that simply won't run due to 24H2 is that it requires a processor capability that has been available since first generation Intel Core processors. It should run on your hardware in a VM. Seems like something else is going on.