I'll say again... Hyper V is only needed if running VM machines. It should NOT be affecting the ability to enable Memory Integrity. I've shown/explained this perfectly via my posted images. And though the OP has a pre-built machine, the rules should be the same.
I also provide a way to test said theory.
Not here to determine who the greatest technician is, simply trying to help the OP. I'm also not here to argue. The OP can do with the info I provided as they wish.
Peace
2nd time in a row (in this topic alone) you read between lines and just rubbish on what's being said by others (makes no sense in relation to what i said). Not to mention - you don't know what you're talking about (you don't seem to understand this feature - how it works and its requirements). Quite ironic - since Memory Integrity is also known as
Hypervisor-protected Code Integrity (it's in the name). That beings said - do try yourself what you recommended him to do...
"Not saying Hyper V isn't the issue -
It can be tested by simply disabling Hyper V (Virtualization) in the BIOS. If no change (still can't enable Memory Integrity), I'd move on from that train of thought. On the other hand, if the OP
IS running VM software, they might check there."
As anything is possible in PCs, please be aware
Hyper V should not be affecting the ability to enable Memory Integrity. I have the exact same reading as the OP, and yet Memory Integrity is enabled on my machine.
View attachment 58164
View attachment 58165
As to this...
You would only need
Hyper V if running any Virtual Machines. I myself run no Virtual Machines requiring Hyper V to be enabled, but simply enable it in the BIOS by default. Point... I have the same readings as the OP, yet my Memory Integrity is enabled.
All that said, what I find interesting is the missing faulty driver info (and why I asked to see Device Manager). There should be something there listing the affected driver. The fact that there is nothing there suggests (simply "my guess") the issue may actually be a "missing" driver, and why, I asked to see Device Manager.
Not saying Hyper V isn't the issue - It can be tested by simply disabling Hyper V (Virtualization) in the BIOS. If no change (still can't enable Memory Integrity), I'd move on from that train of thought. On the other hand, if the OP
IS running VM software, they might check there.
My two cents.
Then try to Enable Memory Integrity (after
simply disabling Virtualization from Bios). Unless this feature was reworked last night (completely changed the way it works and its requirements) - you won't even find the page to be able to access Memory Integrity - let alone be able to Enable it. It's actually because you have Virtualization Enabled - why you're able to run it. Here, the official info:
Memory integrity is
a virtualization-based security (VBS) feature available in Windows. Memory integrity and VBS improve the threat model of Windows and provide stronger protections against malware trying to exploit the Windows kernel. VBS
uses the Windows Hypervisor (Hyper-V Platform > Hyper-V Hypervisors) to create an isolated virtual environment that becomes the root of trust of the OS that assumes the kernel can be compromised. Memory integrity is a critical component that protects and hardens Windows
by running kernel mode code integrity within the isolated virtual environment of VBS. Memory integrity also restricts kernel memory allocations that could be used to compromise the system.
This article explains the steps to opt in to using memory integrity on Windows devices.
learn.microsoft.com
Also, knowing this stuff has very little to do with being a good technicians (that's more about years upon years of practice - only way you can learn this trade) - and more to do with reading about this features while checking their functionality in practice (if you actually care or are into learning about this stuff - since for 99.99% of world's population is not actually useful or interesting - nor will you find them on Windows relates forums talking about this features) - especially since the information is public (like above link). Instead, of...
forming personal conclusion about how they might work (which is clearly what you did - only way you could make such statements like above). Last but not least - since you also got this part wrong - thus the info/content you share as knowledge is actually misleading - which is the opposite of helping others (more like - confusing the OP about the subject in question - by advising one to disable a BIOS feature - which is actually a core requirement for using this security feature). Also from official info:
"Many third-party virtualization applications don't work together with Hyper-V. Affected applications include VMware Workstation and VirtualBox. These applications might not start virtual machines, or they may fall back to a slower, emulated mode.These symptoms are introduced when the
Hyper-V Hypervisor (which is needed for Memory Integrity to work) is running.
Cause
This behavior occurs by design.
Many virtualization applications depend on hardware virtualization extensions that are available on most modern processors. It includes Intel VT-x and AMD-V. Only one software component can use this hardware at a time. The hardware cannot be shared between virtualization applications.
To use other virtualization software, you must disable
Hyper-V Hypervisor (again, needed for Memory Integrity to work), Device Guard, and Credential Guard. If you want to disable Hyper-V Hypervisor, follow the steps in next two sections.
Learn why virtualization applications don't work alongside Hyper-V, Device Guard, and Credential Guard, and how to resolve the issue.
learn.microsoft.com
PS. Sometimes even having enough experience paired with knowledge - one can still be wrong - like using this feature on 10 year old hardware - which all things consider (didn't work when i tried that myself in practice + taking into account the official info it shouldn't work) - i was sure it can't/doesn't work. Yet, was proven wrong. And that info is actually more valuable to me (since it expands my knowledge) - than my pride (which more often than not makes people more stupid). As mentioned above - some things one can only learn from practice (as it's usually the case with a new OS). But this is not the case - "thus, i wasted my time while writing this message (since i'm sure you're not gonna read it - like you didn't read the others - or else you wouldn't make such statements) - not for you - but for anyone reading your personal conclusion - and getting less knowledgeable in the process (if they actually take your personal conclusions as actual knowledge on this subject). Peace out.
on the pile: As reported 
Stay tuned.
