I have a question concerning software updates. Currently I install new releases into a different folder each time. The user is then required to re-enter configuration parameters. This of course is not too optimal. The software is Windows forms and I use the settings. Settings file. So the question is what happens if I install a newer version into the same folder as a previous install? Will files just get replaced? What about if I have added settings in the new version? Will they be merged? Anything to watch out for? Thanks
When the MSIs are related, typically you can only have one instance of it installed at a time. If that's the case, first the earlier version may be uninstalled, so the question is whether the files that store the settings are removed by uninstalling your MSI.
If the MSIs are not related, you can get into a world of pain by overlapping their installations (probably breaking component rules by having two different components describe the same file in the same location, but with a different component code), yet the core question comes down to the same thing: will the updated installation lay down the file that stores the settings.
These are likely the same question, as the easiest way to remove or install a file is by including it in the MSI directly. (There are other ways, but I'm assuming you're not using those yet.) If the file is not part of the installation, nothing will happen to it, and the answer to your question comes down to what your application does when it runs with a settings file created in a different version. If the file is part of the installation, and component rules are not being broken, it will either be uninstalled then freshly installed (wiping any configuration), or per File Versioning Rules and Default File Versioning, the file will either be left untouched or completely replaced with the new version. Windows Installer doesn't know how to merge your settings file.