VT-x is not available issue - Windows 10

Question

Tried to start my virtual machine on VirtualBox after a normal update on windows 10. But getting the issue

VT-x is not available (VERR_VMX_NO_VMX)

Before the update everything was working fine. Searching for the issue tells to enable virtualization in BIOS which I have checked is enabled.

Virtualization in BIOS

Hyper-V in Control Panel

Solutions I have tried

1. Turning off Hyper-V with dism.exe /Online /Disable-Feature:Microsoft-Hyper-V-All following a reboot. but doesn't work.

Solution

Windows 10 Core isolation memory might be activated. This is stealing VT-x !

To see if it is activated check this:

Check Windows Defender

If you have this activated, deactivate it by setting the following registry key to 0

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\DeviceGuard\Scenarios\HypervisorEnforcedCodeIntegrity\Enabled

Comments

[Nauman Zafar]

@Biswa I have added the screenshot. Please check.

[Nauman Zafar]

Just Windows Defender

[Biswapriyo]

@NaumanZafar May be you've to disable all the Hyper-V features. Put /all options in your dism command. Or disable all the Hyper-V features in Optional Features in control panel.

[Nauman Zafar]

@Biswa Hyper-V is completely disabled from CP.. I have added the screenshot.

[Dunken]

Did you find a solution to this? I have the same issue...

[I say Reinstate Monica]

@Ramhound I trust your recommendation that this is a duplicate, but I'm not seeing how this question duplicates the other. Can you clarify what I'm missing?

[Ramhound]

I believe I must have confused. I flagged this as a duplicate due to the answer it recently received. Given this was asked in Sept 2017, Core Isolation is unlikely the culprit. When I see "answers" by extremely new users which I know are duplicates of an existing question's answer, I sometimes will flag the question, as a duplicate of the question with that answer. Instead of putting my foot in my mouth by submitting a comment. The flag was withdrawn.

[Ramhound]

This question has had three different answers deleted that all suggested Core Isolation was the cause of the author’s problem which of course isn’t possible due to fact Core Isolation wasn’t a Windows 10 feature at the time the author asked the question. So I am going to protect it.