Sophos Anti-Virus SBE: "Fatal error during installation. 0x80041f09 sau"

The following error may be displayed when installing the Sophos AutoUpdate component of Sophos Anti-Virus Small Business Edition (SBE):

"Fatal error during installation. 0x80041f09 sau"

The following errors will also be observed in the Event Viewer:

Type: Warning, Source MsiInstaller, Category: None, Event ID: 1015 Description: Failed to connect to server. Error 0x80004005

and

Type: Error, Source: MsiInstaller, Category: None, Event ID: 1014, Description: Windows Installer proxy not correctly registered.

The above errors can be encountered if the Microsoft Windows Installer installation is either incomplete, or corrupt.

What to do

To solve this, re-register MsiExec:

No visible change will take place. However, if you run the setup program again, it should now work.

If this method fails, you will need to reinstall the Microsoft Windows Installer (MSI). Consult the Microsoft website for details of how to do this.

If you need more information or guidance, then please contact technical support.