Virtual machines are missing, or error 0x800704C8, 0x80070037, or 0x800703E3 occurs when you try to start or create a virtual machine

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Article ID: 961804 - View products that this article applies to.
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Important This article contains information that shows you how to help lower security settings or how to turn off security features on a computer. You can make these changes to work around a specific problem. Before you make these changes, we recommend that you evaluate the risks that are associated with implementing this workaround in your particular environment. If you implement this workaround, take any appropriate additional steps to help protect the computer.
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When you try to create or start a Hyper-V virtual machine on a computer that is running Windows Server 2008, Windows Server 2008 R2, Microsoft Hyper-V Server 2008, or Microsoft Hyper-V Server 2008 R2, you experience one of the following problems:
  • You receive one of the following error messages:

    Error message 1
    The requested operation cannot be performed on a file with a user-mapped section open. (0x800704C8)
    Error message 2
    VMName’ Microsoft Synthetic Ethernet Port (Instance ID{7E0DA81A-A7B4-4DFD-869F-37002C36D816}): Failed to Power On with Error 'The specified network resource or device is no longer available.' (0x80070037).
    Error message 3
    The I/O operation has been aborted because of either a thread exit or an application request. (0x800703E3)
  • Virtual machines disappear from the Hyper-V Management Console.


This problem may be caused by antivirus software that is installed in the parent partition if the real-time scanning component is configured to monitor the Hyper-V virtual machine files.


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Warning This workaround may make a computer or a network more vulnerable to attack by malicious users or by malicious software such as viruses. We do not recommend this workaround but are providing this information so that you can implement this workaround at your own discretion. Use this workaround at your own risk. If your system performance or stability is improved by the recommendations that are made in this article, contact your antivirus software vendor for instructions or for an updated version of the antivirus software. For more information, click the following article number to go to the article in the Microsoft Knowledge Base:

822158 Virus scanning recommendations for Enterprise computers that are running currently supported versions of Windows

To resolve this problem, configure the real-time scanning component within your antivirus software to exclude the following directories and files:
  • Default virtual machine configuration directory (C:\ProgramData\Microsoft\Windows\Hyper-V)
  • Custom virtual machine configuration directories
  • Default virtual hard disk drive directory (C:\Users\Public\Documents\Hyper-V\Virtual Hard Disks)
  • Custom virtual hard disk drive directories
  • Custom replication data directories, if you are using Hyper-V Replica
  • Snapshot directories
  • Vmms.exe (Note: This file may have to be configured as a process exclusion within the antivirus software.)
  • Vmwp.exe (Note: This file may have to be configured as a process exclusion within the antivirus software.)
Additionally, when you use Live Migration together with Cluster Shared Volumes, exclude the CSV path "C:\Clusterstorage" and all its subdirectories.

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  • If virtual machines are missing from the Hyper-V Management console, you must configure the antivirus exclusions, and then restart the Hyper-V Virtual Machine Management service.
  • If you receive error code 0x800704C8, the virtual machine configuration file was likely corrupted. If you receive this error, and you cannot resolve the issue by restarting the Hyper-V Virtual Machine Management service, the virtual machine must be re-created or restored from a backup.

More information

To protect your virtual machines, we recommend that you install the antivirus software within the virtual machine.

For more information about best practices for Hyper-V security, go to Planning for Hyper-V Security on the Microsoft TechNet website.


Article ID: 961804 - Last Review: July 12, 2013 - Revision: 15.1
Applies to
  • Microsoft Hyper-V Server 2008
  • Microsoft Hyper-V Server 2008 R2
  • Windows Server 2008 Standard
  • Windows Server 2008 Enterprise
  • Windows Server 2008 Datacenter
  • Windows Server 2008 R2 Datacenter
  • Windows Server 2008 R2 Enterprise
  • Windows Server 2008 R2 Standard
  • Windows Server 2012 Standard
  • Windows Server 2012 Datacenter
kbhyperv kberrmsg kbtshoot kbexpertiseinter kbsurveynew kbprb kbsmbportal KB961804

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