FIX: When you run Windows Update to scan for updates that use Windows Installer, including Office updates, you may experience a memory leak, or you may receive an error message for the Svchost process

When you run Microsoft Windows Update to scan for updates or to apply updates to any applications that use Microsoft Windows Installer (MSI) 3.1 together with Windows Update, you may receive the following error message in Event Viewer on a Windows XP-based computer:Additionally, a memory leak may occur when Windows Update scans for updates that use Windows Installer.

These problems may occur when you try to scan for Microsoft Office updates. You may also experience these problems when you use any one of the following update mechanisms:

• The Microsoft Update Web site.
• Automatic Updates through the Internet or through Windows Server Update Services (WSUS).
• Microsoft Systems Management Server Inventory Tool for Microsoft Updates (SMS ITMU).
• Microsoft Baseline Security Analyzer (MBSA).
• Any application that performs update scans by using the offline scan CAB file (Wsusscan.cab) that uses the Windows Update Agent (WUA).

For example, you may experience this problem when you try to scan for Microsoft Office updates or when you apply an update to any application on a computer that uses Microsoft Windows Installer 3.1 (also known as MSI) together with the Windows Update Agent.

This problem may occur when the Windows Update Agent tries to scan for Windows Installer updates.

Hotfix information

To resolve this problem, apply the latest Msi.dll hotfix. This hotfix is described in the following Microsoft Knowledge Base article:

Hotfix replacement information

The hotfix that was described in this article (916089) has been replaced by a more recent hotfix (927891). Hotfix 927891 includes the updates that are listed in this article. When Windows Update scans for updates that use Windows Installer, the system may stop responding. Hotfix 927891 resolves this problem.

This problem was corrected in Windows Update Agent 3.0 and update 927891.

This update decreases the duration of a scan that uses the Windows Update Agent. However, a scan is still a CPU-intensive operation. The Svchost.exe process contains the Automatic Updates service. When you perform a scan, the Svchost.exe process can cause CPU usage to reach 100 percent for a prolonged time. For example, Microsoft Office updates use Windows Installer. When Microsoft Office updates are detected, these updates can contribute to 100 percent CPU usage for a prolonged time.

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

If you are still experiencing a problem that resembles the one that this article describes, it may be a different problem. For more information about similar problems and resolutions, click the following article numbers to view the articles in the Microsoft Knowledge Base: If these articles do not help you resolve the problem or if you experience symptoms that differ from those that this article describes, please search the Microsoft Knowledge Base for more information. To search the Microsoft Knowledge Base, visit the following Microsoft Web site: Then, type the text of the error message that you receive, or type a description of the problem in the Search Support (KB) field.