Hyper-V error reference · with fixes
Hyper-V throws some of the most cryptic errors I’ve ever had to babysit. So I built myself this lookup, and figured you’d want it too. Type the code or paste the message. Describing the symptom works too. You get the cause and the exact steps that clear it, whether that’s a PowerShell line or a BIOS toggle. Sometimes it’s just the one permission fix that actually sticks. Click any error to open the fix. Want to narrow things down? Filter by category: install, memory, network, VM, checkpoint, coexistence. The whole thing runs in your browser, no server in the loop.
How to use this Hyper-V error reference
The thing that makes Hyper-V so maddening to debug? One problem wears a different mask every time you meet it. Sometimes it’s a clean hex code (0x80070569). Other times it’s a whole paragraph of a sentence (“The virtual machine could not be started because the hypervisor is not running”). And sometimes you get a useless shrug like “failed to change state” and nothing else. Which face you see mostly comes down to where you ran into it, the Manager versus PowerShell versus some buried event-log line. So I grouped the common ones here, each with a root cause and a numbered fix you can just follow. Search any chunk of the code or the message, or filter by category, and open the card.
After enough late nights, I’ve come to think almost everything lands in one of six buckets, and honestly I’d be a little surprised if you find something that doesn’t. The role or hypervisor not coming up at boot. Not enough RAM to start a VM. Virtual switch and networking binding messes. File-permission and config snags when you drag VMs around. Checkpoint and saved-state failures. And the eternal turf war with other virtualization software (VMware, VirtualBox, WSL2, Credential Guard). Name the bucket and the fix is usually sitting right there.
The three checks that solve most Hyper-V failures
- Is virtualization actually on? Open Task Manager → Performance → CPU and look for Virtualization: Enabled. Disabled? Flip on Intel VT-x or AMD SVM in the BIOS/UEFI. Then power-cycle the box. Not a restart. A real cold boot, all the way off and back, because some firmware only commits the toggle that way.
- Is the hypervisor launching at boot? Run
bcdedit /enum {current}and check thathypervisorlaunchtypereadsAuto. If it doesn’t, set it withbcdedit /set hypervisorlaunchtype autoand reboot. This is the whole fix more often than it has any right to be. - Do the VM files have the right permissions? Copy a VHDX between folders or drives and the per-VM virtual account quietly drops its access. No warning, nothing. Re-add the disk in VM Settings, or grant the SID back by hand with
icacls.
When the dialog won’t tell you anything useful, the event log will. Pull the worker log with Get-WinEvent -LogName Microsoft-Windows-Hyper-V-Worker-Admin -MaxEvents 20, and glance at the VMMS log Microsoft-Windows-Hyper-V-VMMS-Admin while you’re there. The real story behind a vague “failed to change state” usually sits in one of those two, naming the actual file or permission that broke.
When the error is not listed
Don’t see your exact code? Grab the full message and the matching event-log entry. Then ask one question: which operation actually died on you, the start, the checkpoint, the import, the network? That answer plus the event-log detail tends to drop you straight into one of the categories above. If a config is too mangled to bother repairing, the Hyper-V PowerShell generator rebuilds the VM from scratch for you. And the CTF lab on Hyper-V walkthrough hands you a known-good setup to diff against, for those moments when you genuinely can’t remember what “normal” was supposed to look like.
Privacy and how this tool runs
The entire error dataset ships inside the page, and the search is plain JavaScript running on your machine. Nothing you type leaves the browser. It isn’t logged, and it isn’t stored. Once the page has loaded you can pull the network cable and it keeps working. Which matters more than it sounds, since a dead host is usually the exact moment you’ve got no internet to look anything up.
Frequently asked questions
Why does Hyper-V say “the hypervisor is not running”?
Nearly always a short list. CPU virtualization is off in the BIOS. The hypervisor isn’t set to launch at boot (hypervisorlaunchtype is off). Or some other piece of software grabbed the virtualization extensions before Hyper-V could. Turn on VT-x/AMD-V in firmware, run bcdedit /set hypervisorlaunchtype auto, then reboot. And if VMware’s installed or Memory Integrity is switched on, you’ll have to settle that fight too, because the extensions only ever go to one owner.
How do I fix Hyper-V error 0x80070569?
It’s a logon failure on the VHDX. The VM’s virtual account lost its NTFS access, and nine times out of ten that’s because you copied the disk somewhere or restored it from backup. Easiest fix: open VM Settings, remove the disk, add it straight back. Hyper-V re-stamps the permission for you. Prefer doing it by hand? Run 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?
On VMware Workstation 16 or newer, you’re fine. It rides the Windows Hypervisor Platform and sits happily next to Hyper-V. Stuck on something older? Then you’ve got to tear Hyper-V and VBS down: turn off Core Isolation Memory Integrity, run bcdedit /set hypervisorlaunchtype off, then reboot. Honestly, if it were my box I’d just upgrade VMware and skip the whole dance. The toggle list for the old way is longer than it has any business being, and the coexistence guide walks through every step of it.
What causes “insufficient system resources” (0x800705AA)?
Your host doesn’t have the free RAM to back the VM’s startup memory at that moment. So hand it less. Drop the startup RAM, or flip on Dynamic Memory with a smaller minimum. Close the browser tabs and IDEs quietly eating the rest. Or just put more sticks in the box. Before you retry, peek at committed memory in Task Manager. If it’s pinned up near the limit, well, there’s your culprit.
Why can’t I import a VM (“configuration version not supported”)?
The VM was built on a newer Windows than the host you’re importing it into. And here’s the bit that trips people up: you can’t downgrade a configuration version. There’s just no flag for it. So either import it on a host that’s the same Windows build or newer and run Update-VMVersion, or spin up a fresh VM on the old host and attach the existing VHDX to that. Want to see what your host will swallow before you start? Get-VMHostSupportedVersion.
How do I read the real reason behind a generic Hyper-V error?
Skip the dialog entirely and go straight to the operational event logs. Run Get-WinEvent -LogName Microsoft-Windows-Hyper-V-Worker-Admin -MaxEvents 20 for VM worker failures, and check Microsoft-Windows-Hyper-V-VMMS-Admin for management-service trouble. One of them names the exact file or permission or resource that set off that vague “failed to change state”. The dialog itself will only ever shrug at you anyway.
Sources & further reading
- Microsoft Learn, Hyper-V on Windows Server overview
- Microsoft Learn, Hyper-V on Windows (client)
- Microsoft Learn, Windows Server troubleshooting
