Fix HYPERVISOR_ERROR (0x00020001) in Windows 11

HYPERVISOR_ERROR with the code 0x00020001 appears when something goes wrong inside the layer that runs underneath Windows and hosts virtual machines. In practice it shows up most often at one specific moment: you start a virtual machine, the system freezes, the screen goes black, and the stop code appears.

This guide explains which settings create the conflict and how to resolve it, including what to do when the change leaves the PC unable to boot.

PAGE CONTENT

• What HYPERVISOR_ERROR Means
• Check Whether a Virtualization Feature Is Running
• Fix 1: Confirm Hardware Virtualization and Windows Features
• Fix 2: Turn Off the Hypervisor Launch Type
• Fix 3: Turn Off Memory Integrity
• Fix 4: Disable Virtualization-Based Security by Policy
• Recover If Windows Will Not Boot
• FAQs About HYPERVISOR_ERROR
• Back Up and Restore Windows with Qiling Disk Master

What HYPERVISOR_ERROR Means

A hypervisor is the software layer that creates and manages virtual machines. Windows ships with one, and it is used by more than Hyper-V: virtualization-based security, Memory Integrity, Windows Sandbox, and the virtual machine platform all depend on it.

When the hypervisor fails, the whole platform underneath Windows fails with it, which is why this stop code is severe rather than cosmetic. The realistic triggers are narrow:

• Third-party virtualization software such as VMware Workstation or VirtualBox competing with the Windows hypervisor for the same hardware
• Memory Integrity, also called HVCI, rejecting a driver that is incompatible with its checks
• Virtualization features left half-enabled, where some components are on and others are off
• Hardware virtualization disabled or unstable in firmware
• Conflicts with third-party antivirus software that also hooks virtualization

Check Whether a Virtualization Feature Is Running

Step 1. Open Task Manager, go to the Performance tab, select CPU, and look at the Virtualization line. "Enabled" confirms that firmware support is active.

Step 2. Open Windows Security > Device Security > Core Isolation and check the state of Memory Integrity.

Step 3. Open Turn Windows features on or off and review the Hyper-V entries, Virtual Machine Platform, Windows Hypervisor Platform, and Windows Sandbox.

Step 4. Note the combination you find. If Memory Integrity is on, or if any hypervisor-related feature is enabled, you have found the likely source of the conflict. If everything is off and you still crash, move on to the firmware checks.

Fix 1: Confirm Hardware Virtualization and Windows Features

Step 1. Restart and enter BIOS or UEFI setup. Confirm that Intel VT-x or AMD-V is enabled, since a disabled or unstable virtualization setting produces failures as soon as a virtual machine starts.

Step 2. Save and exit, then check in Task Manager that the Virtualization line reads "Enabled".

Step 3. Open the Windows features list and clear these entries: Hyper-V, Virtual Machine Platform, Windows Hypervisor Platform, and Windows Sandbox.

Step 4. Restart and test the same action that used to crash, such as starting a virtual machine.

Step 5. If the crash continues, do not stop here. Go on to disable the hypervisor launch type as described below, because the feature list alone does not control whether the hypervisor starts.

Fix 2: Turn Off the Hypervisor Launch Type

This is the step most guides miss, and it is the one that resolves the majority of virtualization software conflicts.

Step 1. Open Command Prompt as administrator.

Step 2. Run the following command to stop the Windows hypervisor from launching at boot:

bcdedit /set hypervisorlaunchtype off

Step 3. Restart the PC. The command takes effect only after a restart, so do not test the virtual machine before rebooting.

Step 4. Start your virtual machine again. If it now runs normally, the conflict was between the Windows hypervisor and your virtualization software.

Step 5. Remember this setting. Any Windows feature that needs the hypervisor, such as Windows Sandbox or Memory Integrity, will not work until you switch it back on with:

bcdedit /set hypervisorlaunchtype auto

Fix 3: Turn Off Memory Integrity

Memory Integrity is a virtualization-based security feature, also known as hypervisor-protected code integrity. It runs kernel-mode code integrity checks inside an isolated environment created by the hypervisor.

That isolation is valuable, but it is also strict. Microsoft documents that some applications and hardware device drivers are incompatible with Memory Integrity, and that this incompatibility can cause devices or software to malfunction and, in rare cases, result in a boot failure.

Step 1. Open Windows Security > Device Security > Core Isolation details.

Step 2. If Memory Integrity is on and the page lists incompatible drivers, review that list before doing anything else. Updating or removing those drivers is the better fix, because it preserves the protection.

Step 3. If you cannot resolve the incompatible driver, turn Memory Integrity off and restart.

Step 4. Test the action that previously triggered the stop code.

Step 5. Note the performance context: Memory Integrity works best on Intel Kaby Lake and newer processors with mode-based execution control, and on AMD Zen 2 and newer with guest mode execution trap. On older processors Windows emulates these features in a mode known as restricted user mode, and the performance cost is noticeably higher.

Fix 4: Disable Virtualization-Based Security by Policy

If Memory Integrity is greyed out, or if the setting returns after a restart, a policy is enforcing it.

Step 1. Open the Local Group Policy Editor and navigate to Computer Configuration > Administrative Templates > System > Device Guard.

Step 2. Set Turn On Virtualization Based Security to Disabled.

Step 3. On a domain-joined machine, this setting normally comes from your organization. Contact your administrator rather than overriding a corporate security policy on your own.

Step 4. Restart the PC and test again.

Step 5. Also check for third-party antivirus software. Some security products hook virtualization for their own sandboxing features and can produce the same conflict. Temporarily removing one is a valid test, provided you reinstall it afterwards.

Step 6. Finish with system file repairs, since corrupted components can also destabilise the security stack:

DISM /Online /Cleanup-Image /RestoreHealth
sfc /scannow

Recover If Windows Will Not Boot

Changing virtualization and security settings can, in some configurations, leave the PC unable to start. Here is how to get back in.

Step 1. Try to reach Safe Mode or the Recovery Environment. From the sign-in screen, hold Shift while selecting Restart. If the PC never reaches that screen, force three failed startups by holding the power button during boot; on the third attempt Windows should offer the recovery options.

Step 2. Disable any policy that enables virtualization-based security or Memory Integrity, for example through Group Policy, since the policy will otherwise reapply the setting you are trying to remove.

Step 3. Boot into the Windows Recovery Environment and open Command Prompt.

Step 4. Set the Memory Integrity scenario value to off in the registry. The setting lives under HKLM\SYSTEM\CurrentControlSet\Control\DeviceGuard\Scenarios\HypervisorEnforcedCodeIntegrity, where the Enabled value should be 0.

Step 5. If BitLocker prompts for a recovery key before you can run any command, retrieve that key first. See our guide on the BitLocker recovery key after a Windows update if it is not where you expected.

Step 6. Restart normally. Once Windows starts, re-enable the protections that do not conflict with your virtualization software.

FAQs About HYPERVISOR_ERROR

Why does the blue screen appear only when I start a virtual machine?

Because that is the moment both hypervisors try to claim the processor's virtualization extensions. The conflict exists all the time but only becomes fatal when the second one starts.

I unchecked Hyper-V and still get this error. Why?

Because the Windows hypervisor can continue to run independently of the Hyper-V feature list. You must also disable the hypervisor launch type and turn off Memory Integrity.

Is turning off Memory Integrity safe?

It reduces protection against kernel-level malware, so it is a tradeoff rather than a free fix. Update or remove the incompatible driver if you can, and restore the setting when the conflict no longer exists.

Can third-party antivirus cause this stop code?

Yes. Some security products use virtualization for sandboxing and conflict with the Windows hypervisor. Temporarily removing one is a common and effective test.

What does 0x00020001 mean?

It is the bug check code for a hypervisor error. It tells you the failure occurred in the virtualization layer rather than in a normal driver, which is why the fixes focus on hypervisor and security settings.

Will a Windows reset fix it?

Not by itself. Users have reported that the error returns after a full reset, because the conflict is created by software and settings that get reinstalled or reapplied. Fix the configuration instead.

Back Up and Restore Windows with Qiling Disk Master

Changing hypervisor, Memory Integrity, and firmware settings can leave a machine that will not start, and recovering from that is far easier with an image than with a repair attempt. Create a full system backup before you begin. Qiling Disk Master handles both the backup and the restore.

• Free Download
• Windows 11/10/8/7, 100% Secure

Part 1: Create a Full System Backup

Step 1. Install and open Qiling Disk Master. On the home screen, open "Backup and Recovery" and choose "System Backup". This option automatically includes Windows and the hidden boot partitions, so you do not have to select them one by one.

Step 2. Check the source. The disk where Windows is installed and its system partitions are already ticked for you. If you only need your personal documents, run a separate "File Backup" task instead.

Step 3. Click the destination box and choose where the image should be saved. Use an external HDD or SSD, a NAS, or any drive other than the one Windows is installed on, and make sure it has enough free space.

Step 4. Review the task summary and click "Proceed". Wait until the progress bar reaches 100%. Do not unplug the drive or turn off the PC while the backup is running.

Part 2: Restore Windows from the Backup

Step 1. Open Qiling Disk Master again, go to "Backup and Recovery", and select the recovery option. Your backup images are listed, so pick the one you created before the changes began.

Step 2. Choose the target disk or partition. Normally you restore to the original system disk. If the drive was replaced, select the new disk instead, and the restore rebuilds Windows together with its boot partitions.

Step 3. Preview the restore plan, click "Proceed", and confirm the warning. The PC restarts to finish the job, and Windows comes back exactly as it was on the day the image was created, with your files and programs intact.

Conclusion

HYPERVISOR_ERROR means the virtualization layer underneath Windows failed, and it usually appears when your virtualization software and the Windows hypervisor compete for the same processor features. Unchecking Hyper-V is not enough, because the hypervisor can keep running regardless. Confirm that hardware virtualization is enabled, disable the hypervisor launch type with bcdedit /set hypervisorlaunchtype off, turn off Memory Integrity if a driver is incompatible, and clear any policy that enforces virtualization-based security. Restore those protections once the conflicting software is gone.

Protect your PC with Qiling Backup—create a system image before your next troubleshooting step.

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