I'm working on a new version of an application, which would be a major upgrade to the existing installation, with a new product code for the new version. I'd like to let the user choose at runtime whether to upgrade the existing installation in place or to install the new version side-by-side, in a different location. Is this possible? It's a Basic MSI project.
What you want to consider is multiple instance MSI's and a bootstrapper that can let a chooser decide between installing a new instance and upgrading an existing instance similar to the way InstallScript projects work.
Thanks for the suggestion--I'll look into your approach. However, my scenario is simpler than yours, since I don't need multiple instances of the same version installed. I'm wondering if it would work if I set the upgrade properties in InstallShield to detect the prior version without automatically updating, then prompt from the UI sequence and take the appropriate action. Isn't there a property that the bootstrapper passes to tell the installer to do the upgrade instead of a parallel installation?
Well perhaps you could enforce a different destination directory and then conditionalize RemoveExistingProducts to leave the orginally installed product alone.
I get around this because each instance automatically defaults to a different destination directory and they all belong to different upgradecode families since only a newer version targeting the same instance would be a major upgrade.
This gives me a lot of flexibility in installing instances/versions not previously thought of until someone needed to do it.
