Trace events in the log output are randomly lost on a Windows Vista-based computer that has the ETW trace log enabled

On a Windows Vista-based computer, you enable the Event Tracing for Windows (ETW) trace log. After you extract a large .psf file, and then you exam the log output, some trace events are randomly lost. If you extract the .psf file again, you may find that a random subset of the trace events is lost.

This issue occurs because the event tracing session runs out of free buffers. When high event rates are processed at the same time, the disk subsystem becomes overloaded. In this case, the event tracing session randomly discards some events instead of holding the process until more buffers become available.

Service pack information

To resolve this problem, obtain the latest service pack for Windows Vista. For more information, click the following article number to view the article in the Microsoft Knowledge Base:

Hotfixes and security updates that are included in SP2 for Windows Vista Service and for Windows Server 2008

For more information about the hotfixes and the security updates that are included in SP2 for Windows Vista and for Windows Server 2008, visit the following Microsoft TechNet Web site: -Note: Currently, the list of hotfixes and security updates is available only in English.

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. 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.

Prerequisites

There are no prerequisites for installing this hotfix.

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 Vista, x86-based versions

Windows Vista, x64-based versions

Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section. This problem was first corrected in Windows Vista Service Pack 1.

For more information about Event Tracing, visit the following Microsoft Web sites: For more information about how to use Event Tracing, visit the following Microsoft Web site:For more information about software update terminology, click the following article number to view the article in the Microsoft Knowledge Base: