Win11 build 22581 broke VB by enabling Credential Guard

[sgadsby]

FYI:

When Win11 build 22581 was pushed to my machine I found that my Windows VMs would start but run very slowly. Found that Windows was reporting in msinfo32 and systeminfo that Hyper-V was now running even though all Hyper-V features were disabled.

Resolution:

• Disable Virtualisation Based Security (which includes Credential Guard)

Steps:

• Download Device Guard and Credential Guard readiness tool from https://www.microsoft.com/en-us/downloa ... x?id=53337
• Run the included .ps1 with -Disable switch
• On reboot choose to disable VBS

This script from Microsoft boots SecConfig.efi to disable VBS. I recommend using this tool because gives you a tool to easily switch it back on later if you need, but alternatively you can just run the commands from the following post, which also contains a good description of how it works:

• https://superuser.com/questions/1124753 ... uard-and-r

[mpack]

Please do not use five year old third party discussion sites as authorities. Tutorials published on this site (which we keep up to date) and the user manual (which the devs keep up to date) are the only authorities recognized here.

The relevant tutorial on this site is: HMR3Init: Attempting fall back to NEM (Hyper-V is active).

[fth0]

I for one appreciated this well-formulated post, including the 5-year-old background information.