wix installer - supporting upgrade and more than one installation at the same time

Question

I know that you can upgrade the versions, remove the old the installation and install the new version.
and I know you can also support two installations of the same software on the same machine.

Is there a way to create a GUI installation which let's the user choose if he wants to upgrade or keep the old version and install the new instance in addition to old the ones?

Answer 1

Yes, but it's not simple.

Basically you start with two upgrade table entries. One that is fake and would never detect a product and one that detects your previous versions but has the DetectOnly attribute set.

Next you need to create a custom dialog with a radio button ( install new, upgrade existing ) and a list box to contain the entries of previously detected products. You will use a custom action to populate the ListBox table with temporary rows to reflect the previous qualifying products to be upgraded.

If the user selects Install new, you just carry on. If they select upgrade existing you parse out the product codes from the Detect Only upgrade action property and put them into the "fake" action property. Now remove existing products will have something to remove.

They are all kinds of business rules you'll want to come up with and enforce, cover the silent installation story and also have a way of mutating the INSTALLDIR so the products can be side by side.

That's the basic pattern but you'll have to come up with all the details around it. I've done this several times with very favorable results.