Error message when you use Event Viewer to open an event log on a Windows Vista or a Windows Server 2008-based computer: "Event Viewer cannot open the event log or custom view"

On a computer that is running Windows Vista or Windows Server 2008, you cannot use Event Viewer to open an event log. Additionally, you receive an error message that resembles the following: When this problem occurs, if you run a customer application that uses the Windows Event Log application programming interface (API) to read the contents of the event log (.evtx) files, the application fails and you receive the ERROR_INVALID_DATA error message.

Note By default, .evtx files are located under the following directory:

This problem occurs when an .evtx file is corrupted. In an .evtx file, there is a string table that stores strings of events so that duplicate strings can be saved only one time. Other strings reference the strings stored in the table by using the index of the table. Every time that a new event is generated, new strings are added to the table. Sometimes, an event cannot be written to the event log file. However, part of the string table is already updated. In this situation, the .evtx file is corrupted.

There is a hotfix to prevent this problem. After you apply this hotfix, the update to the string table will roll back if the event is not written to the .evtx file. In this manner, the .evtx file is not corrupted. However, this hotfix cannot recover a corrupted .evtx file.

If you install this hotfix on a computer that has a corrupted .evtx file, you must clear and back up the corrupted log by using the Wevtutil command. For example, to clear and to back up the log to the System.evtx file, run the following command:

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 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.

Prerequisites

To apply this hotfix, your computer must be running one of the following operating systems:

• Windows Vista Service Pack 1 (SP1)
• Windows Vista Service Pack 2 (SP2)
• Windows Server 2008
• Windows Server 2008 Service Pack 2 (SP2)

Restart requirement

You must restart the computer after you apply this hotfix.

Registry information

You do not have to make any change to the registry.

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 file information note

The MANIFEST files (.manifest) and MUM files (.mum) installed for each environment are listed separately . MUM and MANIFEST files, and the associated security catalog (.cat) files, are important to maintaining the state of the updated component. The security catalog files (attributes not listed) are signed with a Microsoft digital signature.

For all supported x86-based versions of Windows Vista and Windows Server 2008

For all supported x64-based versions of Windows Vista and Windows Server 2008

For all supported Itanium-based versions of Windows Server 2008

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

For more information about the Windows Event Log service, visit the following Microsoft Web site:For more information about Windows events, visit the following Microsoft Web site:For more information about how to use the Wevtutil command, visit the following Microsoft Web site: For more information, click the following article number to view the article in the Microsoft Knowledge Base: