This setting specifies the location from which the setup launcher can download InstMsiA.exe, the installer for the Windows 9x Windows Installer engine, if necessary. This setting is ignored unless the MSI Engine Location setting for the current release is set to Download Engine from the Web. Do not specify the file name in the URL

The default URL (http://www.installengine.com/Msiengine20) is a site maintained by Macrovision for your convenience; the http://www.installengine.com/cert02/Msiengine site is also maintained by Macrovision. The 2.0 engines are available for download from the http://www.installengine.com/Msiengine20 location, and the 1.2 engines are available from the http://www.installengine.com/cert02/Msiengine location.