Latest Dev Channel builds of Win 11 fail to install with Workstation Tech Preview

[elbert]

Attempting to install Win 11 Dev Build 25179 results in a blue screen noting an unsupported processor even when the underlying physical system has a fully supported CPU. This issue also occured when attemping to install Win 11 Dev Build 25179 with VMWare 15 and 16 versions. Win 11 Dev Build 25179 successfully installed on physical host machine. Also tested Win 11 Dev Build 25179 using the "LabConfig" registry settings during setup installation on Oracle Virtual Box, installation was succesfull. Additionally tested installation on host machine with Intel i9-9900K CPU and installation was successful on all version of VMWare (15, 16, and Tech Preview) Previous builds before 25179 installed successfully on all host machines.

Test scenario:

Host machine

Win 11 22H2

32GB RAM

Intel i7-11700

VMware Config

Installing Win 11 Dev Channel build 25179

TPM installed

8GB RAM assigned

1 CPU and 2 cores assigned

Encryption set to encrypt only necessary files

Secure boot not enabled

UEFI BIOS selected

[wila]

Attach the vmware.log file of the VM.

--
Wil

[elbert]

See atch logs for windows 11 host buids 25179 and the just release 25182.  By the way, I'm getting the same error when trying to install Server vNext build 25179 as a host.

[wila]

Hi,

As expected your log has the following line:

2022-08-17T14:44:31.132Z In(05) vmx Monitor Mode: ULM

Which means that you are running in User Level Mode and thus Workstation cannot use VMware's hypervisor, but instead it has to go through the Hypervisor API that Microsoft provides.

Only when Monitor mode returns CPL0 it is running in ring 0, a.k.a. no hypervisor. This is required for VMware Workstation to be able to use their own hypervisor.

see also:

https://communities.vmware.com/t5/VMware-Workstation-Pro/MikroTik-RouterOS-boot-speed-is-drastically...

In order to turn off User Level mode, run the following command at the host in windows command-line with Administrator privileges:

bcdedit /set hypervisorlaunchtype off

Reboot the system to activate your changes.

If you want to go back to ULM/Hyper-V mode again, then you can enable it like this:

bcdedit /set hypervisorlaunchtype auto

See also:

• Workstation 16 Pro Error "Virtualized Intel VT-x/EPT is not supported on this platform
• https://kb.vmware.com/s/article/2146361

Note that you also might have to disable Memory Integrity.

Windows Security -> Device Security -> Core Isolation details

Don't forget to reboot the host after making any of these changes.

--
Wil

[lesliewong]

Thank you @wila, for your suggestions. I was having the green screen error, Stop code: UNSUPPORTED PROCESSOR when I tried to install the last two Windows Insider developer builds, 25182 and 25179.

I ran the command that you suggested, 

bcdedit /set hypervisorlaunchtype off

and my VM then was able to update to the current Windows Insider dev channel preview build, 25182.

[elbert]

Finally resolved this issue.  Removed VMWare from Dell XPS 8940 and installed VMWare on a custom made PC with Gigabyte motherboard with Z590 chipset, ran the bcdedit /set hypervisorlaunchtype off command and I was able to installed and upgrade the W11 host to the latest version, build 25188.. For some reason The latest W11 builds do not run as a host on VMWare on Dell XPS 8940.  Maybe it has something to do with the H chipset used on those motherboards.

[lenh51]

@wila    - Your instructions regarding changing the VMX Monitor Mode worked perfectly for me and I was able to install the latest Insider Version (25197).  A few questions which I hope you will not mind answering

1) How come this was not a problem previously (The last build I was able to install prior to today was 25174)?  

2) Are there any other advantages or disadvantages to leaving hypervisorlaunchtype set to off? 

Thanks so much for your help.  

Len 

[wila]

Hi,

1) Hard to say. Microsoft hides specific Windows features behind their virtualisation layer. So you turn on feature X and they turn on their hypervisor. Or.. it might be turned on because of an update or because you updated Windows (going from Windows 10 to Windows 11 being a prime example)

2) Biggest advantage of turning it off is that you can use VMware's own hypervisor and enjoy all of its the features. Disadvantages are basically what is described in the steps to disable:
- no hyper-V
- no WSL2
- no core isolation
- no Windows Sandbox
- no Credential Guard/Device Guard

Personally I rather have VMware's hypervisor and if I want any of those features, then I use them in the guest, not the host. For me that works, but that might not be for everyone.

--
Wil