VMware Workstation and Device/Credential Guard are not compatible

I'm still not convinced that Hyper-V is The Thing for me, even with last year's Docker trials and tribulations and I guess you won't want to switch very frequently, so rather than creating a new boot and confirming the boot default or waiting out the timeout with every boot I switch on demand in the console in admin mode by

bcdedit /set hypervisorlaunchtype off

Another reason for this post -- to save you some headache: You thought you switch Hyper-V on with the "on" argument again? Nope. Too simple for MiRKoS..t. It's auto!

Have fun!
G.

There is a much better way to handle this issue. Rather than removing Hyper-V altogether, you just make alternate boot to temporarily disable it when you need to use VMWare. As shown here...

http://www.hanselman.com/blog/SwitchEasilyBetweenVirtualBoxAndHyperVWithABCDEditBootEntryInWindows81.aspx

C:\>bcdedit /copy {current} /d "No Hyper-V" 
The entry was successfully copied to {ff-23-113-824e-5c5144ea}. 

C:\>bcdedit /set {ff-23-113-824e-5c5144ea} hypervisorlaunchtype off 
The operation completed successfully.

note: The ID generated from the first command is what you use in the second one. Don't just run it verbatim.

When you restart, you'll then just see a menu with two options...

• Windows 10
• No Hyper-V

So using VMWare is then just a matter of rebooting and choosing the No Hyper-V option.

If you want to remove a boot entry again. You can use the /delete option for bcdedit.

First, get a list of the current boot entries...

C:\>bcdedit /v

This lists all of the entries with their ID's. Copy the relevant ID, and then remove it like so...

C:\>bcdedit /delete {ff-23-113-824e-5c5144ea}

As mentioned in the comments, you need to do this from an elevated command prompt, not powershell. In powershell the command will error.

update: It is possible to run these commands in powershell, if the curly braces are escaped with backtick (`). Like so...

C:\WINDOWS\system32> bcdedit /copy `{current`} /d "No Hyper-V"

Device/Credential Guard is a Hyper-V based Virtual Machine/Virtual Secure Mode that hosts a secure kernel to make Windows 10 much more secure.

...the VSM instance is segregated from the normal operating system functions and is protected by attempts to read information in that mode. The protections are hardware assisted, since the hypervisor is requesting the hardware treat those memory pages differently. This is the same way to two virtual machines on the same host cannot interact with each other; their memory is independent and hardware regulated to ensure each VM can only access it’s own data.

From here, we now have a protected mode where we can run security sensitive operations. At the time of writing, we support three capabilities that can reside here: the Local Security Authority (LSA), and Code Integrity control functions in the form of Kernel Mode Code Integrity (KMCI) and the hypervisor code integrity control itself, which is called Hypervisor Code Integrity (HVCI).

When these capabilities are handled by Trustlets in VSM, the Host OS simply communicates with them through standard channels and capabilities inside of the OS. While this Trustlet-specific communication is allowed, having malicious code or users in the Host OS attempt to read or manipulate the data in VSM will be significantly harder than on a system without this configured, providing the security benefit.

Running LSA in VSM, causes the LSA process itself (LSASS) to remain in the Host OS, and a special, additional instance of LSA (called LSAIso – which stands for LSA Isolated) is created. This is to allow all of the standard calls to LSA to still succeed, offering excellent legacy and backwards compatibility, even for services or capabilities that require direct communication with LSA. In this respect, you can think of the remaining LSA instance in the Host OS as a ‘proxy’ or ‘stub’ instance that simply communicates with the isolated version in prescribed ways.

And Hyper-V and VMware didn't work the same time until 2020, when VMware used Hyper-V Platform to co-exist with Hyper-V starting with Version 15.5.5.

How does VMware Workstation work before version 15.5.5?

VMware Workstation traditionally has used a Virtual Machine Monitor (VMM) which operates in privileged mode requiring direct access to the CPU as well as access to the CPU’s built in virtualization support (Intel’s VT-x and AMD’s AMD-V). When a Windows host enables Virtualization Based Security (“VBS“) features, Windows adds a hypervisor layer based on Hyper-V between the hardware and Windows. Any attempt to run VMware’s traditional VMM fails because being inside Hyper-V the VMM no longer has access to the hardware’s virtualization support.

Introducing User Level Monitor

To fix this Hyper-V/Host VBS compatibility issue, VMware’s platform team re-architected VMware’s Hypervisor to use Microsoft’s WHP APIs. This means changing our VMM to run at user level instead of in privileged mode, as well modifying it to use the WHP APIs to manage the execution of a guest instead of using the underlying hardware directly.

What does this mean to you?

VMware Workstation/Player can now run when Hyper-V is enabled. You no longer have to choose between running VMware Workstation and Windows features like WSL, Device Guard and Credential Guard. When Hyper-V is enabled, ULM mode will automatically be used so you can run VMware Workstation normally. If you don’t use Hyper-V at all, VMware Workstation is smart enough to detect this and the VMM will be used.

System Requirements

To run Workstation/Player using the Windows Hypervisor APIs, the minimum required Windows 10 version is Windows 10 20H1 build 19041.264. VMware Workstation/Player minimum version is 15.5.5.

To avoid the error, update your Windows 10 to Version 2004/Build 19041 (Mai 2020 Update) and use at least VMware 15.5.5.