Windows Server 2008 Hyper-V systems restart unexpectedly, and you receive a 0x1000007E Stop error code when you mount a VHD file

Applies to: Windows Server 2008 DatacenterWindows Server 2008 EnterpriseWindows Server 2008 Standard


When you mount a virtual hard disk (VHD) file, Windows Server 2008 Hyper-V systems restart unexpectedly, and you receive the following Stop error code:
For example, you use Windows Server 2008 Virtual Machine Manager (VMM) to convert a physical drive to a virtual drive. If you use VMM to mount the captured image, the Windows Server 2008 system may experience this problem.


When a VHD file is corrupted, the Volsnap.sys driver may handle it incorrectly. This causes the Volsnap.sys driver to access freed memory and triggers the 0x1000007E Stop error code.


A supported hotfix is available from Microsoft. However, this hotfix is intended to correct only the problem that is described in this article. Apply this hotfix only to systems that are experiencing the problem described in this article. This hotfix might receive additional testing. Therefore, if you are not severely affected by this problem, we recommend that you wait for the next software update that contains this hotfix.

If the hotfix is available for download, there is a "Hotfix download available" section at the top of this Knowledge Base article. If this section does not appear, contact Microsoft Customer Service and Support to obtain the hotfix.

Note If additional issues occur or if any troubleshooting is required, you might have to create a separate service request. The usual support costs will apply to additional support questions and issues that do not qualify for this specific hotfix. For a complete list of Microsoft Customer Service and Support telephone numbers or to create a separate service request, visit the following Microsoft Web site: Note The "Hotfix download available" form displays the languages for which the hotfix is available. If you do not see your language, it is because a hotfix is not available for that language.


To apply this hotfix, you must be running Windows Server 2008 with Hyper-V on the computer.

Restart requirement

You have to restart the computer after you apply this hotfix.

Hotfix replacement information

This hotfix does not replace a previously released hotfix.

File information

The English version of this hotfix has the file attributes (or later file attributes) that are listed in the following table. The dates and times for these files are listed in Coordinated Universal Time (UTC). When you view the file information, it is converted to local time. To find the difference between UTC and local time, use the Time Zone tab in the Date and Time item in Control Panel.

Windows Server 2008 file information notes

The .manifest files and the .mum files that are installed in each environment are listed separately in the "Additional file information for Windows Server 2008 and for Windows Vista" section. These files and their associated .cat (security catalog) files are critical to maintaining the state of the updated component. The .cat files are signed with a Microsoft digital signature. The attributes of these security files are not listed.
For all supported versions of Windows Server 2008 with Hyper-V
File nameFile versionFile sizeDateTimePlatform
Volume.infNot Applicable2,08211-Nov-200800:29Not Applicable


Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.

More Information

For more information about software update terminology, click the following article number to view the article in the Microsoft Knowledge Base:
824684 Description of the standard terminology that is used to describe Microsoft software updates

Additional file information for Windows Server 2008

Additional files for all supported versions of Windows Server 2008 with Hyper-V
File nameFile versionFile sizeDateTimePlatform
Amd64_volume.inf_31bf3856ad364e35_6.0.6001.22306_none_7264f557cd8a9e25.manifestNot Applicable1,67311-Nov-200817:37Not Applicable
Package_for_kb959766_client_1~31bf3856ad364e35~amd64~~ Applicable1,37511-Nov-200817:23Not Applicable
Package_for_kb959766_client~31bf3856ad364e35~amd64~~ Applicable1,43911-Nov-200817:23Not Applicable
Package_for_kb959766_sc_0~31bf3856ad364e35~amd64~~ Applicable1,42911-Nov-200817:23Not Applicable
Package_for_kb959766_sc~31bf3856ad364e35~amd64~~ Applicable1,43111-Nov-200817:23Not Applicable
Package_for_kb959766_server_0~31bf3856ad364e35~amd64~~ Applicable1,43311-Nov-200817:23Not Applicable
Package_for_kb959766_server~31bf3856ad364e35~amd64~~ Applicable1,43911-Nov-200817:23Not Applicable
Package_for_kb959766_winpesrv_0~31bf3856ad364e35~amd64~~ Applicable1,43011-Nov-200817:23Not Applicable
Package_for_kb959766_winpesrv~31bf3856ad364e35~amd64~~ Applicable1,43711-Nov-200817:23Not Applicable