Differentiating between uninstalling/installing and upgrading an application

Question

So, I have this application for which we are producing further development versions.

If the application gets uninstalled by the user (from Add/Remove Programs let's say), then I want the application to delete a certain folder in the file system which contains app-related information.

However, if the application is upgraded (by downloading a newer installer for this app and installing it), then I want it to keep that folder.

I am under the impression (at the moment) that it is not possible to differentiate between uninstalling/installing and just updating an application from one version to another, because the .NET deployment projects treat upgrading as just another uninstall/install procedure, but this should be possible somehow.

Thanks for taking the time and whatever answers I may get.

Answer 1

The installer has three GUID codes, ProductCode, PackageCode and UpgradeCode that you can use to manage these scenarios: The UpgradeCode is like an application id and shouldn't change between versions; the PackageCode identifies a release of your setup and the ProductCode identifies a release of your software. You can change the ProductCode by incrementing the ProductVersion value.

Windows uses the ProductCode to see if the application is already installed on a system. If you reinstall using an installer with the same ProductCode and PackageCode you get a Repair/Uninstall option.