While uninstalling an application, windows installer removes shared files used by other applications. -2. the windows installer service contains a reference to an installation directory where the application files reside. -while uninstalling applications, windows installer does not delete the shared files required by other applications. it only removes the files related with the application that is uninstalled. the windows installer service uses the windows installer package file that contains information needed to install or uninstall software. the contents of this file include a windows installer file with a .msi extension, any external source files required for installation or uninstallation, summary information about the software and the package, and the product files or a reference to their installation directory.