Installation of an assembly on a Windows XP-based computer is not successful, and a message is logged in the verbose log file: "skipping installation of assembly component: {ID} since the assembly already exists"

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When you try to install an assembly on a Windows XP-based computer, the installation is not successful. If you enable the verbose Windows Installer Logging feature to troubleshoot this problem, you may find a message that resembles the following in the verbose log file:
MSI (s) (9C:A0) [Time]: skipping installation of assembly component: {ID} since the assembly already exists
  • This issue occurs if an application has already installed the assembly or if the directory for the assembly exists.
  • This issue also occurs during an assembly maintenance installation process. For example, this issue also occurs during the repairing process, the patching process, and the uninstalling process.
This issue occurs because of an error in the fusion component and the Windows Installer 3.x component.

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.

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.


To apply this hotfix, the computer must run Windows XP Service Pack 2.

Restart requirement

You have to 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 XP Service Pack 2, x86-based version
File nameFile versionFile sizeDateTimePlatform
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
More information
For more information about how to enable Windows Installer logging, click the following article number to view the article in the Microsoft Knowledge Base:
314852 How to Enable Windows Installer Logging in Windows XP
For more information, click the following article number to view the article in the Microsoft Knowledge Base:
824684 Description of the standard terminology that is used to describe Microsoft software updates

Article ID: 941971 - Last Review: 01/16/2015 09:42:22 - Revision: 2.0

Microsoft Windows XP Home Edition, Microsoft Windows XP Professional

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