Hyper-V Virtual Machines Stuck Starting at 10% when Network Adapter is Connected

Question

I am unable to start new or existing Hyper-V virtual machines on a Windows 10 Enterprise version 20 H2 laptop (build 19042.685) when a network adapter is attached. Each VM hangs at 10% on startup. ![47572-image.png][1] After a number of minutes the start-up times out with the following error message displayed. ![47556-image.png][2] In Event Viewer the following four events are logged: ![47582-image.png][3] ![47458-image.png][4] ![47562-image.png][5] ![47591-image.png][6] If you disconnect the network adapter from the VM's they start successfully. I have already tried removing and reinstalling the Hyper-V components within Windows 10 using "Turn Windows features on or off" but this has not resolved the issue. The Windows 10 machine is fully patched up to date including the December 2020 Cumulative Update and is running Windows Defender as the anti-virus solution. Any assistance on how to resolve or troubleshoot this issue further will be most appreciated. Thank you. [1]: /api/attachments/47572-image.png?platform=QnA [2]: /api/attachments/47556-image.png?platform=QnA [3]: /api/attachments/47582-image.png?platform=QnA [4]: /api/attachments/47458-image.png?platform=QnA [5]: /api/attachments/47562-image.png?platform=QnA [6]: /api/attachments/47591-image.png?platform=QnA

Answer 1

Hi，

What is the virtual switch the VM connects to? Please open Virtual switch manager, check if the virtual switch is in good state, pleasek provide the screenshot of the virtual switch.

If it is an external virtual switch, please check if the network adapter driver is up to date, if not, please update the NIC driver.

After updating the NIC driver, please delete the external virtual switch and recreate it, check if it could work.

Besides, please try to disconnect the VM to the virtual switch, then start the VM, check if the VM can be started.

Thanks for your time!
Best Regards,
Anne

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Answer 2

The root cause of the issue was “Authenticated Users” being in the local administrators group of the device. Removing “Authenticated Users” from the local administrators group resolved the issue.