Specify whether the files of the active component (the component selected in the Setup Design or Components view) overwrite already-existing versions on the target system always, never, or conditionally based on date/time stamp or version number.

You may wish to use the "Never overwrite" option for components consisting of files your end user may have updated, such as data and configuration files.

Files associated with a component that is marked "Never overwrite" are logged for uninstallation; that is, even if such a file is not copied to the target system, because a file with the same name already exists there, that file is removed when the application is uninstalled. To prevent an already existing file from being uninstalled, set the Shared property of the file's component to Yes.