Hyper-V error reference · with fixes
Search a Hyper-V error by its code, message or symptom and get the cause and the exact steps to resolve it — the PowerShell command, the BIOS toggle or the permission fix that actually clears it. Click any error to expand the resolution. Filter by category to browse install, memory, network, VM, checkpoint and coexistence problems. Runs entirely in your browser.
How to use this Hyper-V error reference
Hyper-V surfaces failures as a mix of hexadecimal codes (0x80070569), long sentences (“The virtual machine could not be started because the hypervisor is not running”) and vague generic messages (“failed to change state”). The same underlying problem often appears under several wordings depending on whether you hit it in Hyper-V Manager, PowerShell or the event log. This reference groups the common ones and, for each, gives the root cause and a numbered fix you can follow immediately. Type any part of the code or message into the search box, or filter by category, then expand the card to see the resolution.
Most Hyper-V problems fall into six buckets: the role or hypervisor not starting at boot, not enough memory to start a VM, virtual switch and networking binding issues, file-permission and configuration problems when moving VMs, checkpoint and saved-state failures, and conflicts with other virtualization software (VMware, VirtualBox, WSL2, Credential Guard). Knowing the bucket usually points straight at the fix.
The three checks that solve most Hyper-V failures
- Is virtualization actually on? Open Task Manager → Performance → CPU and confirm Virtualization: Enabled. If not, enable Intel VT-x or AMD SVM in the BIOS/UEFI and do a full power cycle.
- Is the hypervisor launching at boot? Run
bcdedit /enum {current}and checkhypervisorlaunchtypeisAuto. Set it withbcdedit /set hypervisorlaunchtype autoand reboot. - Do the VM files have the right permissions? After copying a VHDX between folders or drives, the per-VM virtual account loses access. Re-add the disk in VM Settings or grant the SID with
icacls.
Read the matching event log for the precise failure: Get-WinEvent -LogName Microsoft-Windows-Hyper-V-Worker-Admin -MaxEvents 20 and the VMMS log Microsoft-Windows-Hyper-V-VMMS-Admin hold the real reason behind a generic “failed to change state”.
When the error is not listed
If your exact code is not here, capture the full message and the event log entry, then search for the operation that failed (start, checkpoint, import, network). The combination of operation plus event-log detail almost always maps to one of the categories above. The companion Hyper-V PowerShell generator helps you rebuild a VM cleanly when a configuration is too broken to repair, and the CTF lab on Hyper-V walkthrough covers a known-good setup you can compare against.
Privacy and how this tool runs
The whole error dataset is embedded in the page and the search runs in your browser with plain JavaScript. Nothing you type is sent to a server, logged or stored. The reference works offline once the page has loaded.
Frequently asked questions
Why does Hyper-V say “the hypervisor is not running”?
Either CPU virtualization is disabled in the BIOS, the hypervisor is not set to launch at boot (hypervisorlaunchtype is off), or another component is holding the virtualization extensions. Enable VT-x/AMD-V in firmware, run bcdedit /set hypervisorlaunchtype auto and reboot. If you also run VMware or have Memory Integrity on, resolve that conflict too.
How do I fix Hyper-V error 0x80070569?
This is a logon-failure on the VHDX: the VM’s virtual account lost NTFS access, usually after the disk was copied or restored. Open the VM Settings, remove the disk and re-add it (Hyper-V regenerates the permission), or grant it manually with icacls "path\disk.vhdx" /grant "NT VIRTUAL MACHINE\<VM-GUID>:(F)" where the GUID comes from (Get-VM name).Id.
How do I run VMware Workstation and Hyper-V at the same time?
VMware Workstation 16 and later use the Windows Hypervisor Platform and coexist with Hyper-V. On older versions you must disable Hyper-V and VBS: turn off Core Isolation Memory Integrity, run bcdedit /set hypervisorlaunchtype off, and reboot. See the dedicated coexistence guide for the full toggle list.
What causes “insufficient system resources” (0x800705AA)?
The host does not have enough free RAM for the VM’s startup memory. Lower the VM’s startup RAM, enable Dynamic Memory with a smaller minimum, close memory-hungry host apps, or add physical memory. Check committed memory in Task Manager before retrying.
Why can’t I import a VM (“configuration version not supported”)?
The VM was created on a newer Windows build than the host you are importing it to. You cannot downgrade a configuration version. Import it on a host with an equal or newer Windows version and run Update-VMVersion, or recreate the VM on the older host and attach the existing VHDX. Check supported versions with Get-VMHostSupportedVersion.
How do I read the real reason behind a generic Hyper-V error?
Open the operational event logs: Get-WinEvent -LogName Microsoft-Windows-Hyper-V-Worker-Admin -MaxEvents 20 for VM worker failures and Microsoft-Windows-Hyper-V-VMMS-Admin for management-service issues. They contain the specific file, permission or resource that triggered the vague “failed to change state”.
