Dave Simm's Blog: Hyper-V Machine Creation Error (0×80070037)

On an existing Hyper-V server that was previously working fine, i stumbled across the error below while trying to create a new guest machine.

An error occurred while attempting to change the state of virtual machine SERVER.

‘SERVER’ failed to start.

Microsoft Synthetic Ethernet Port (Instance ID {E4BAFA29-EB7E-4CD9-98A5-59546CEA6AE5}): Failed to power on with Error ‘The specified network resource or device is no longer available.’

‘SERVER’ failed to start. (Virtual machine 2A23B1CF-0758-4AF5-84B1-221BA2A8A90D)

‘SERVER’ Microsoft Synthetic Ethernet Port (Instance ID {E4BAFA29-EB7E-4CD9-98A5-59546CEA6AE5}): Failed to power on with Error ‘The specified network resource or device is no longer available.’ (0×80070037). (Virtual machine 2A23B1CF-0758-4AF5-84B1-221BA2A8A90D)

I narrowed this down to be a combination of a few things.

I had added a new location for hyper-v vhd/xml files and hadn't excluded that new location from realtime AV scanning
Secondly, the version of MS Forefront AV client i was running on the server required an update to version 1.5.1958.0
Thirdly, i excluded .vhd files from realtime scanning.

And don't forget to bounce the server, or at the very least the services for hyper-v afterwards!

Official Microsoft info here... http://support.microsoft.com/default.aspx?scid=kb;EN-US;961804

2 comments:

Unknown4 February 2015 at 03:58
This year’s breakout film at the Sundance Film Festival, timberland outlet uk Tangerine, is full of surprises according to The Verge, from the story in front of the camera to the shooting timberland outlet sale behind the camera. The camera in question wasn’t even a camera but an iPhone 5S. Plenty of films have been made with cheap timberland boots iPhones but this is by far the most successful and first to make it to Sundance.
Matt Calder5 November 2025 at 07:31
This is a solid troubleshooting rundown. The failure message can be misleading, so calling out AV scanning as the real culprit is helpful. Hyper-V really does not behave well when its VHD and config directories are scanned in real time. Your step list is exactly what most admins miss:

Add exclusions for the new storage path

Update the Forefront client

Exclude .vhd extensions from scanning

Restart Hyper-V services or reboot the host

Also sharing the Microsoft KB link saves others time.

If anyone needs to track systems, test steps, or repeatable runbooks for infra environments, a lightweight tool like Tuskr test management software is useful for documenting what to check next time this pops up.