8 Fixes: VT-X Is Not Available (verr_vmx_no_vmx) On Virtual Machines

When you attempt to start a virtual machine with the VirtualBox application, you get the Vt-X Is Not Available (Verr_vmx_no_vmx) error on your computer. It’s most likely because virtualization has been turned off.

8 Best Fix Vt-X Is Not Available (Verr_vmx_no_vmx) On Virtual Machines

In most cases, you can disable or enable VT-x in your BIOS. When your computer is first turned on, press DEL (or something similar) to access the BIOS settings. There’s an option to enable VT technology there. 

I recommend reading this post, which explains how to resolve the Vt-X Is Not Available (Verr_vmx_no_vmx) problem and why it was triggered in the first place.

What Causes Vt-X Is Not Available (Verr_vmx_no_vmx) Issue In Computer Machine?

I looked into the problem by attempting to reproduce it and reviewing other user reports. Several scenarios, as far as I can tell, will result in the appearance of this error message:

  • VT-X is not activated in the BIOS: VT-X can be disabled manually or remotely in the BIOS settings by some 3rd party apps. It will cause the Vt-X Is Not Available (Verr_vmx_no_vmx) issue.
  • The CPU does not support VT-X: Although rare, there are times when the error occurs because the PC in question lacks the necessary hardware to implement the VT-X technology.
  • Windows Hyper-V virtualization is enabled: Microsoft’s Hyper-V technology interferes with VT-X. If Hyper-V virtualization is permitted, the OS will automatically disable VT-x.
  • VT-X was disabled after an Avast update: Avast just published an update that effectively disables VT-x. At the same time, real-time protection is active unless the user chooses to activate nested virtualization from the settings menu.
  • Core Isolation is turned on: When you enable the Core isolation option on your machine, it can cause issues with the VirtualBox application, resulting in the VT-x being unavailable (VERR VMX NO VMX) problem. As a result, we recommend turning off this feature and seeing whether the problem goes away.

Answer To Fix Virtualbox Vt-X Is Not Available (Verr_vmx_no_vmx) Error?

  1. Disable Core Isolation From Windows Defender
  2. Enable Vt-X From Bios Settings (Boot Menu)
  3. Disable Hyper-V Virtualization System (Windows Hypervisor)
  4. Enable Nested Virtualization In Avast
  5. Disable Kernel Isolation In Windows Defender
  6. Disable Windows Sandbox
  7. Disable Device Guard / Credential Guard
  8. Uninstalling Third-Party Antivirus Software
  9. Enable Virtualization

1. Disable Core Isolation From Windows Defender

Windows Defender Device security option Core Isolation is known to conflict with VT-X. If you’re experiencing the Vt-X Is Not Available (Verr_vmx_no_vmx) issue and using Windows Defender as your default security option, I recommend seeing if Core isolation is turned on.

  • Search for Windows Defender using the start icon in the bottom-left corner.
  • To access the built-in security feature, go to Windows Defender Security Center and click on it.
  • In Windows Defender Security Center, go to the left-hand menu and select Device security.
Windows Defender Security Center
  • Select Core isolation details from the Device Security menu (under Core isolation ).
Select Core isolation details
  • Ensure the toggle linked with Memory integrity is switched off in the Core isolation menu.
Memory integrity is switched off
  • Reboot the computer after disabling the setting to see if the problem has been fixed at the next startup.
  • Check if you were able to fix the “Vt-X Is Not Available (Verr_vmx_no_vmx)” issue or not.

2. Enable Vt-X From Bios Settings (Boot Menu)

This problem can also be caused by the Virtualization Technology option being disabled in the BIOS settings. Therefore make sure to verify and enable this option if it is currently disabled. 

Vt-X Is Not Available (Verr_vmx_no_vmx) to issue, most likely because the technology is disabled in your BIOS settings. Some third-party applications may override these settings, so don’t discard this method until you’ve checked to see if this is the case.

Depending on your motherboard manufacturer, the steps for accessing the BIOS settings and confirming if VT-X is enabled will differ. This parameter is indicated as Virtualization Technology or VTx/VTd under Security (System Security).

  • To enter “BIOS Mode,” first “Boot” your computer and then hit the setup button when the “Windows Logo” shows on your screen.
"BIOS Mode
  • Move to the “Security” tab and scroll down to “System Security” once in BIOS mode.
  • Locate the “Virtualization Technology (VTx/VTd)” option and ensure it is “Enabled.” If it isn’t already enabled, go ahead and do so.
Virtualization Technology (VTx/VTd)"
  • “Reboot” the computer. Check if you were able to fix the “Vt-X Is Not Available (Verr_vmx_no_vmx)” issue or not.

3. Disable Hyper-V Virtualization System (Windows Hypervisor)

Make sure Hyper-V virtualization isn’t interfering with VT-x first. When Hyper-V virtualization is enabled or On, the VT-x virtualization equivalent is immediately disabled. The update broke Hyper-functioning. V’s

You may be experiencing this issue as a result of an application installation. Keep in mind that, in most circumstances, the Hyper-V technology will stay active even if the application that enabled it is uninstalled.

You may disable Hyper-V virtualization in several ways. From a Command Prompt (Admin), follow these steps to disable Microsoft Hyper V:

  • To launch the Run dialog box, hold the Windows key + R. To open an elevated Command Prompt, type “cmd” and hit Ctrl + Shift + Enter. Select Yes when the UAC (User Account Control) window prompts you.
  • To disable Microsoft Hyper V, paste the following commands one by one into the elevated command prompt and hit Enter:
    • bcdedit /set hypervisorlaunchtype Off
    • bcdedit /set vm No
    • dism.exe /Online /Disable -Feature:Microsoft-Hyper-V
dism.exe /Online /Disable -Feature:Microsoft-Hyper-V
  • Close the Command Prompt and reboot the computer once the commands have been completed successfully.
  • Check if you’re still getting the same problem message when you Reboot your Virtualbox computer.
  • Check if you were able to fix the “Vt-X Is Not Available (Verr_vmx_no_vmx)” issue or not.

4. Enable Nested Virtualization In Avast

If you use Avast, be aware that a recent application update added an automatic function that stops VT-X from running on your system if specific criteria are satisfied.

There is a solution to fix this problem without uninstalling the third-party security client.

  • Enable the checkboxes linked with Avast Settings and Troubleshooting, and then Use virtualization nested within virtualization nested within
  • Enable hardware-assisted virtualization, as well.
  • Check if you were able to fix the “Vt-X Is Not Available (Verr_vmx_no_vmx)” issue or not.

5. Disable Windows Sandbox

This problem can also occur if Windows Sandbox is activated on your computer. Simply disable it and then reset your computer. After that, go into BIOS, disable virtualization, and reboot your machine.

Ensure that the virtualization option in your UEFI/BIOS Settings can turn on or off the Windows sandbox on your system.

  • Select and open Task Manager by pressing the Ctrl+Alt+Del shortcut.
  • Check if the Virtualization option is activated on the current page by going to the performance tab.
  • Once validated, use the steps below to enable or disable Windows Sandbox on your Windows 10 computer.
  • Check if you were able to fix the “Vt-X Is Not Available (Verr_vmx_no_vmx)” issue or not.

Control Panel To Enable Or Disable Windows Sandbox.

  • Type Control Panel into the Start Button. To activate this app, double-click on the first choice once more.
  • Select Program, followed by the Programs & Features category, from the visible Window.
  • Tap the “Turn Windows features on or off” option in the left panel.
  • Look for Windows Sandbox in the list beneath the opened window.
  • Then, depending on whether you want to enable or disable this option, activate or deactivate the checkbox.
  • To implement the changes, press the OK button and restart your computer.
  • Check if you were able to fix the “Vt-X Is Not Available (Verr_vmx_no_vmx)” issue or not.

Using Powershell, Enable Or Disable Windows Sandbox

  • Right-click the Start icon and choose PowerShell (Admin) from the drop-down menu.
  • If a UAC prompt occurs, select Yes to allow access.
  • Copy/paste the code into the PowerShell (Admin) window and hit Enter at the end.
  • To enable Windows Sandbox, enter the following code:
    • Enable-WindowsOptionalFeature –FeatureName “Containers-DisposableClientVM” -All -Online
  • Type the following command to turn off Windows Sandbox:
    • Disable-WindowsOptionalFeature –FeatureName “Containers-DisposableClientVM” -Online
  • Select Y to accept the request if the prompt asks you to restart the system after the task is completed.
  • Once the task is completed, check if the sandbox is set to enable or disable, depending on your preference.
  • Check if you were able to fix the “Vt-X Is Not Available (Verr_vmx_no_vmx)” issue or not.

Use The Command Prompt, Enable Or Disable Windows Sandbox

  • Enter cmd into Cortana. Select Run as administrator from the menu when you right-click on Command Prompt.
  • To authorize access, answer Yes to the UAC question.
  • Type the following code into the elevated command prompt and hit Enter to run the command.
  • Copy and paste the code below to enable the Sandbox functionality on Windows.
    • Dism /online /Enable-Feature /FeatureName: “Containers-DisposableClientVM” -All
  • Run this command on Windows to disable the Sandbox feature –
    • Dism /online /Disable-Feature /FeatureName: “Containers-DisposableClientVM”
  • Check if you were able to fix the “Vt-X Is Not Available (Verr_vmx_no_vmx)” issue or not.

6. Disable Device Guard / Credential Guard

By default, a guard or credential guard may be enabled on Windows hosts with an EFI BIOS device. This causes interference with OS-level virtualization software, resulting in the error. To avoid this error, it must be disabled. You can do this on Windows by following the steps below:

  • To enter the Run dialogue box, use the “Window + R” keys together. Type “gpedit.msc” in the dialogue window and hit “Enter.”
  • Navigate to “Local Computer Policy then Computer Configuration then Administrative Templates > System > Device Guard and then Turn On Virtualization Based Security To Disabled” in the Group Editor box.
  • If you cannot do so using the group policy editor, here is another way to accomplish the same goal.
  • Set the value of “keyHKLM > System > CurrentControlSet > Control > DeviceGuard > EnableVirtualizationBasedSecurity > Enabled” to “0” in the registry.
  • Check if you were able to fix the “Vt-X Is Not Available (Verr_vmx_no_vmx)” issue or not.

7. Uninstalling Third-Party Antivirus Software

Any antivirus software installed on your system may be the culprit for this problem. It’s best to uninstall it for a while and see if it fixes the problem. If you’re using the Windows Defender Firewall, you can turn it off by following these steps:

  • Type “Settings” in the search field near the Start menu and press the “Enter” button.
  • Select “Update & Security” from the left pane of the Settings window, then “Windows Security.”
  • Then, under Protection Areas, pick “Virus & Threat Protection” and then “Manage Settings” under Virus & Threat Protection Settings.
Virus & Threat Protection Settings
  • Ensure the toggle for “Real-Time Protection” is turned “OFF” in this window.
  • Return to the “Windows Security” tab and, in the left pane, select “Firewall & Network Protection.”
Firewall & Network Protection.
  • Select “Domain Network,” “Private Network,” and “Public Network” one by one in this box, then switch “OFF” the toggle for “Microsoft Defender Firewall.”
  • Check if you were able to fix the “Vt-X Is Not Available (Verr_vmx_no_vmx)” issue or not.

8. Enable Virtualization

  • Open a command prompt window.
  • Now type systeminfo.exe into the command prompt.
  • To the right of the hyper v requirements, you’ll see virtualization enabled in the firmware.
  • Go to the start menu and select settings from the drop-down menu.
  • Locate and choose Update and Security. A new tab will appear, locate recovery, and click it.
  • You must locate advance startup in recovery and click on the restart now button under advance startup.
click on the restart now button under advance startup.
  • You must click the Troubleshoot option once you see the blue screen with certain icons.
  • Select the Advanced tab. You need to identify that setting because our issue is with the firmware. 
  • Select UEFI firmware settings once we’ve found them, and the restart button will display again; press enters to restart.
Select UEFI firmware settings
  • Locate the BIOS setup and press the appropriate function key.
  • A new panel will appear; navigate to System configuration (you can get here by pressing the arrow keys) and look for Virtualization Technology.
  • At this stage, your virtualization technology is turned on. You can get out of this by pressing F10.
  • Check if you were able to fix the “Vt-X Is Not Available (Verr_vmx_no_vmx)” issue or not.


If virtualization is not enabled on your Windows PC, the error “VT-x is disabled in the BIOS for all CPU modes” displays. Virtualization is disabled by default on many Windows machines at the BIOS level, and it must be activated to create a new virtual machine. To learn what this mistake means and how to fix it, go through all the remedies listed above.