Applications that rely on network resources for installation-on-demand are susceptible to source failures if the source location should change for any reason or become damaged. The Windows Installer provides source resiliency for features that are installed on-demand by using a source list. The source list contains the locations searched by the installer for installation packages. The entries in this list can be network locations, Uniform Resource Locators (URLs), or compact discs. If one of these sources fails, the installer can quickly and seamlessly try the next.
The application developer does not need to incorporate any special information into the installer package to ensure source resiliency. Once the application is installed, the installer has the behavior of adding the last successfully used source as an entry in the source list. By default, this source is the location from which the installer package is initially installed, and is the same as the SourceDir property.
A system administrator can change the source list by applying a transform or by changing the SOURCELIST property from the command line or in the Property table.
