Microsoft KB Archive/303970

= INFO: Windows Installer and Windows File Protection =

Article ID: 303970

Article Last Modified on 10/2/2003

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APPLIES TO


 * Microsoft Windows Installer 1.1
 * Microsoft Windows Installer 1.2

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This article was previously published under Q303970





SUMMARY
The Windows Installer cannot overwrite files that are protected by Windows File Protection (WFP). If your .msi package attempts to update a protected file, you will receive the following error message:

The Windows Installer service cannot update the system file   because the file is protected by Windows. You may need to update your operating system for this program to work correctly. Package version:  , OS Protected version:  &quot;



MORE INFORMATION
When you install an application by using the Windows Installer, you do not have the ability to overwrite protected files. Protected files can only be updated with a system update such as a service pack.

The Windows Installer does not actually attempt to install protected files. The Windows Installer will instead request that WFP install or replace the protected file. WFP will then install or replace the file with a cached version of the file. After WFP has installed the file, the Installer checks this file version against the version information in the file table of the .msi package. If the file version in the package is newer than the installed version, the Installer prompts the user with the error message noted in the &quot;Symptoms&quot; section.

The Installer also checks with WFP when removing files and never attempts to remove protected files.

