There are certain situations where you may want to deploy files permanently to a computer so that they persist through uninstall/re-installs or upgrades. A typical situation in my business is we’ll deploy a config file with default settings. If the settings change, we don’t want them to be lost or overwritten during an upgrade.
By making a very simple modification to your Wix installer, we can get this behavior.
<Component Id="C_Settings.config" Guid="*" NeverOverwrite="yes" Permanent="yes">
The NeverOverwrite attribute ensures that the file will not be overwritten during an upgrade, and the Permanent attribute will cause the file to remain in the program is uninstalled. Perfect!