I'm trying to create a patch/upgrade for my existing application (like example below).
in the latest version of my app, it include a few changes to the file, but no new files (that does not exist in the old app) have been added. I change the version to 2.1.1 with the product name still app1.msi. This new app is still using the same product code as the old app.
My question: What is the best way to create update? Currently, using the same product code, when I launch the installer, it will state that the product have been installed previously. So I need to uninstall existing app first before installing the new version. ( as stated in the help file). Both app was/will be shipped to customer in CD and download version.
One method that I've been using is to change the product code. In this case user can installed the new version over the existing version (the old version will be removed). It is ok for the upgrade but when I create a patch and try to install it in a system that have existing version, it does not work. the installer will prompt error 2356.
Wise Installation Express v7 sp1