We have a requirement that two major versions of our product can be installed on the same client machine in parallel.
I noticed that the default behaviour in InstallShield 2011 with major versions is to systematically remove previous versions and upgrade. Is there a simple way to change that ? Do I have to change Product Code/Upgrade Code for each new major version so that the product is recognized as different and installed without upgrading previous installations ?
The ProductCode must differ for two products to be installed side by side, and when the second product has a Major Upgrade for the first's UpgradeCode, it will generally uninstall the first or block when it's present. By changing both codes, you essentially say that neither product is related to the other in terms of maintenance. So that's probably the route I would take, but to say 100% I'd have to know what your future maintenance updates might be.
