Server stops responding when you lock or unlock files on a network by using the SMB2 protocol in Windows

Applies to: Windows Server 2008 R2 Service Pack 1Windows Server 2008 R2 DatacenterWindows Server 2008 R2 Enterprise

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A computer that is running Windows 7, Windows Server 2008 R2, Windows Vista or Windows Server 2008 stops responding when it uses the Server Message Block Version 2 (SMB2) protocol to lock or unlock files on a network. 

If you enable the special pool feature on the computer, you receive a Stop error message that resembles the following:
STOP: 0x000000D5 ( Parameter1 , Parameter2 , Parameter3 , Parameter4 )

  • The parameters in this Stop error message vary, depending on the configuration of the computer.
  • Not all "0x000000D5" Stop errors are caused by this issue.


This issue occurs because of a race condition between the NTFS file system driver (Ntfs.sys) and the SMB2 server driver (Srv2.sys).

When the race condition occurs, a structure in NTFS file system driver is released prematurely. Therefore, the issue that is described in the "Symptoms" section occurs when the Ntfs.sys driver accesses the released structure.


To resolve this issue, we have released a hotfix package for Windows 7, Windows Server 2008 R2, Windows Vista or Windows Server 2008.

Before you install the hotfix, check the Prerequisites section in this article.

Hotfix information

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 this specific problem.

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, submit a request to 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 install Service Pack 1 for Windows 7 or Windows Server 2008 R2. Or, install Service Pack 2 for Windows Vista and for Windows Server 2008.

Registry information

To use the hotfix in this package, you do not have to make any changes to the registry.

Restart requirement

You must restart the computer after you apply this hotfix.

Hotfix replacement information

This hotfix does not replace a previously released hotfix.

More Information

For more information about the LockFile function, visit the following MSDN website:
For more information about the UnLockFile function, visit the following MSDN website:


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


See the terminology that Microsoft uses to describe software updates.