We have an old project written in pure Install Script. As we are trying to migrate the project to Basic Msi we want to be able to preform updates to the old versions. When we run the Msi installer it does not detect the old pure Install Script product already installed (they have the same product code). I have read on a forum that since the two accomplish upgrades in a different manner causing the msi project to detect a pure Install Script version of the product would not be possible . So what can be done to make the msi project detect the old product already installed?
Not really what I was searching for. The idea was for somehow the msi-setup to detect automatically the previous pure Install Shield version and be able to do an upgrade. I thought maybe there is a setting in the msi project to enable such detection. From that article a manual detection of a previous product could be done, although I do not know if it would improve anything as you won't be able to uninstall the previous product for instance.
Right, there's nothing built in to Windows Installer to detect and then update or remove a product that was installed with something other than Windows Installer. Common practice for MSI removing InstallScript is to use AppSearch to detect and read the old product's uninstall key from the registry, and later run a variation of that command to uninstall the old product.
