An application crashes after the application loads the Perfdisk.dll file on a computer that is running Windows Server 2008 or Windows Vista if there are lots of disk devices on the computer

Consider the following scenario:

• You have lots of disk devices installed on a computer that is running Windows Server 2008 or Windows Vista. For example, you have many logical unit number (LUN) devices on a computer that is running Windows Server 2008 or Windows Vista.
• You use an application that loads the Perfdisk.dll file to read information about disk performance counters. For example, you use the Performance Monitor utility or Microsoft System Center Operations Manager 2007.

In this scenario, the application crashes.

The Perfdisk.dll file queries disk information for disk instances by using a Windows Management Instrumentation (WMI) interface. However, this DLL does not handle the returned disk information correctly. Therefore, this DLL generates an exception if there are many disk instances on the computer. For example, an exception is generated when you have lots of LUN devices or lots of MPIO devices installed on the computer. The exception that is generated by the DLL causes the application to crash.

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.

Important Windows Vista and Windows Server 2008 hotfixes are included in the same packages. However, only one of these products may be listed on the �Hotfix Request� page. To request the hotfix package that applies to both Windows Vista and Windows Server 2008, just select the product that is listed on the page.

Prerequisites

To apply this hotfix, you must have a computer that is running Windows Server 2008, Windows Vista, or Windows Vista Service Pack 1 (SP1).

Restart requirement

You must restart the computer after you apply this hotfix.

Hotfix replacement information

This hotfix does not replace any other previously released hotfixes.

Registry information

To use this hotfix, you do not have to make any changes 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 Server 2008 and Windows Vista note

The MANIFEST files (.manifest) and the MUM files (.mum) that are installed for each environment are listed separately. MUM and MANIFEST files, and the associated security catalog (.cat) files, are critical 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

For all supported x86-based versions of Windows Server 2008 and of Windows Vista SP1

For all supported Itanium-based versions of Windows Server 2008

For all supported x64-based versions of Windows Vista

For all supported x64-based versions of Windows Server 2008 and of Windows Vista SP1

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

For more information, click the following article number to view the article in the Microsoft Knowledge Base:

Additional file information for Windows Server 2008 and for Windows Vista

Additional files for all supported x86-based versions of Windows Server 2008 and of Windows Vista

Additional files for all supported x64-based versions of Windows Server 2008 and of Windows Vista

Additional files for all supported Itanium-based versions of Windows Server 2008