Microsoft Windows Error Code 0xC0021004: How to Fix It

Medium 30 minutes Medium Severity Verified June 2026
Summarize with ChatGPTSummarize with ClaudeSummarize with Perplexity Add as Preferred Source on Google
Error Code
0xC0021004
Brand
Microsoft Windows
Product Type
operating_system
Severity
Medium
DIY Difficulty
Medium
Estimated Fix Time
30 minutes
Error 0xC0021004 in Windows indicates that an invalid hypercall was made to the Hyper-V hypervisor. This typically occurs when software tries to interact with Hyper-V but the hypervisor is not running correctly or is disabled. The fix involves ensuring Hyper-V is properly set up, updating system drivers, or disabling Hyper-V if not needed.
Ad

Tools You'll Need

How to Fix Error Code 0xC0021004

  1. Check If Hyper-V Is Enabled

  2. Enable Hyper-V (If Disabled)

    Enabling Hyper-V may conflict with other virtualization software like VMware or VirtualBox. Disable those first or use nested virtualization.

  3. Update System Firmware and Drivers

    Incorrect BIOS settings can cause system instability. Only change settings you understand.

  4. Repair Hyper-V Installation

  5. Disable Hyper-V (If Not Needed)

    Disabling Hyper-V will stop any running VMs and may affect software that relies on it.

  6. Check for Malware

Ad

When to Call a Professional

If none of the above steps resolve the error, the issue may be hardware-related (e.g., faulty CPU or motherboard). Contact a PC technician for further diagnosis.

Frequently Asked Questions

What is error 0xC0021004 in Windows?
It means a software program attempted to send an invalid command (hypercall) to the Hyper-V hypervisor. This usually indicates Hyper-V is not configured correctly or is disabled.
How do I enable Hyper-V in Windows?
Open PowerShell as Administrator and run: Enable-WindowsOptionalFeature -Online -FeatureName Microsoft-Hyper-V -All. Restart your computer.
Can I ignore error 0xC0021004?
No. The error will cause applications that rely on Hyper-V (like Docker, Windows Sandbox) to fail. You must fix it for those apps to work.
Does error 0xC0021004 mean my CPU is bad?
Usually not. It's typically a software configuration issue. However, if your CPU doesn't support virtualization, Hyper-V cannot run, which causes this error when attempted.
Will disabling Hyper-V fix error 0xC0021004?
Yes, in many cases. If you don't need Hyper-V, disabling it removes the hypervisor interface that triggers the error.

Related Error Codes