We have a product installer created with Wix, containing a program package ("V1") and some configuration files. Now, we are going to make a major upgrade with a new product code, where the old version of the product is uninstalled and "V2" is installed. What we want is to save one of the configuration files from uninstalling, since it is needed for the V2, too. Unfortunately, we forgot to set the Permanent="yes" option when we delivered V1 (read this question for more information).

Here comes the question: is there an easy way of preventing the uninstall of the file anyhow? Of course, we could add a custom action to the script to backup the file before uninstallation, and another custom action to restore it afterwards, but IMHO that seems to be overkill for this task, and might interfere with other parts of the MSI registration process.