From: "Rich Gauszka" 


http://support.microsoft.com/kb/927891

You receive an access violation error and the system may appear to become
unresponsive when you try to install an update from Windows Update or from
Microsoft Update

Note The hotfix that this article describes supersedes the hotfix that
includes the updates that are listed in Microsoft Knowledge Base article
916089.

Note This article discusses the MSI component fixes only. This fix is one
component of a two-part fix that includes a Windows Update client software
update. These updates will be deployed automatically using Windows Update
in May 2007 and June 2007. However, some customers may select to manually
install these updates. To fully address the unresponsive system issue, both
this fix for MSI must be installed and the Windows Update client must be
updated to version 3.0. When you install the MSI fix and the new client,
process-monitoring tools may still show CPU usage at near 100 percent.
However, the system should still be responsive and should not lock up. If
another task requires CPU cycles, they will be shared. However, if the
system is idle, MSI will use the full cycles that are available to complete
in the shortest time. If another task is running at the same time as MSI,
the system may run slightly more slowly. However, the computer should still
be responsive. Remember that you must install the MSI fix and the new
client to address unresponsive or locked systems. It is expected that
process-monitoring tools may still show CPU usage at near 100 percent, but
computer unresponsiveness is expected. If you watch the process monitor,
you may still see CPU usage at near 100 percent during some scans if the
computer is otherwise idle. This is expected behavior.

Important Many instances of the Svchost.exe process may be running on a
Windows-based computer. These Svchost.exe processes control certain tasks.
The software update that is described in this article is only designed to
address the problem that is mentioned in the "Symptoms" section.
Other problems that you experience with Svchost.exe may require alternative
resolutions or troubleshooting steps.

APPLIES TO
      . Microsoft Windows Server 2003, Enterprise Edition (32-bit x86)
      . Microsoft Windows Server 2003, Enterprise x64 Edition
      . Microsoft Windows Server 2003, Datacenter Edition (32-bit x86)
      . Microsoft Windows Server 2003, Datacenter x64 Edition
      . Microsoft Windows Server 2003, Standard Edition (32-bit x86)
      . Microsoft Windows Server 2003, Standard x64 Edition
      . Microsoft Windows XP Professional
      . Microsoft Windows XP Home Edition
      . Microsoft Windows XP Media Center Edition 2002
      . Microsoft Windows XP Media Center Edition 2004
      . Microsoft Windows XP Media Center Edition 2005
      . Microsoft Windows 2000 Professional Edition
      . Microsoft Windows 2000 Service Pack 4
      . Microsoft Windows 2000 Advanced Server
      . Microsoft Windows 2000 Datacenter Server

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