The CPU usage of an application or a service that uses MSXML 6.0 to handle XML requests reaches 100% in Windows Server 2008, Windows Vista, Windows XP Service Pack 3, or other systems that have MSXML 6.0 installed

Consider the following scenario:

1. An application or service runs in Windows Server 2008, Windows Vista, Windows XP Service Pack 3 (SP3) or another system that has Microsoft XML Core Services (MSXML) 6.0 installed.
2. The application or service uses MSXML 6.0 to handle XML requests.

In heavy stress situations, the CPU usage of an application or service reaches 100 percent. If this problem occurs on a uniprocessor computer, the whole system stops responding. If this problem occurs on a multiprocessor computer, the whole system encounters high CPU usage. In Task Manager, you may see that the CPU usage of one processor is 100 percent.

For example, the MonitoringHost.exe process in the System Center Operations Manager 2007 encounters high CPU usage because of this problem.

This problem occurs because MSXML 6.0 does not handle the SpinLock resource correctly in heavy stress situations.

Hotfix information for Windows Vista and Windows Server 2008

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

No prerequisites are required.

Restart requirement

You must restart the computer after you apply this hotfix.

Hotfix replacement information

This hotfix does not replace any other hotfixes.

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 and Windows Server 2008 file information notes

• The files that apply to a specific product, milestone (RTM, SPn), can be identified by examining the file version numbers as shown in the following table:
  Collapse this tableExpand this table

  Version	Product	Milestone	Service branch
  6.0.600 0 . 20 xxx	Windows	RTM	LDR
  6.0.600 1 . 22 xxx	Windows Vista SP1 and Windows Server 2008 SP1	SP1	LDR

• Service Pack 1 (SP1) is integrated into Windows Server 2008. Therefore, RTM milestone files apply only to Windows Vista. RTM milestone files have a 6.0.0000.xxxxxx version number.
• 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 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 RTM

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

For all supported x86-based versions of Windows Server 2008 SP2 and Windows Vista SP2

For all supported x64-based versions of Windows Vista RTM x64

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

For all supported x64-based versions of Windows Server 2008 SP2 and Windows Vista SP2

For all supported IA-64-based versions of Windows Server 2008

For all supported IA-64-based versions of Windows Server 2008 SP2

Hotfix information for Windows XP

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.

Prerequisites

To apply this hotfix, you must have Windows XP SP3 installed on the computer. For more information, click the following article number to view the article in the Microsoft Knowledge Base:

Restart requirement

You must restart the computer after you apply this hotfix.

Hotfix replacement information

This hotfix does not replace any other hotfixes.

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 XP with Service Pack 3, x86-based versions

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

MSXML 6.0 is included with Windows Server 2008, Windows Vista and Windows XP SP3. MSXML 6.0 can be installed in the following operating systems as an Out of Band (OOB) component.

• Windows 2000 Service Pack 4 (SP4)
• Windows Server 2003
• Windows Server 2003 Service Pack 1 (SP1)
• Windows XP SP1
• Windows XP Service Pack 2 (SP2)

To download the latest version of MSXML 6.0, visit following Microsoft Web site: