Support Article: MDBC103

Subject: Windows Installer error 1931 during installation.


For products:

 

SYMPTOMS

During the installation you receive some or all of the following message.

 

The Windows Installer service cannot update the system file <file name> because the file is protected by Windows. You may need to update your operating system for this program to work correctly. Package version: <number>, OS Protected version: <number>"

CAUSE

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 error message.

RESOLUTION

Click OK on the error message and the installation should continue. Receiving this error does not mean the installation will fail. It is likely that Windows is using newer version files than what the installer has. Always be sure to have the latest Service packs and security patches installed on your PC.

 

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 "Symptoms" section.

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