Having an issue with WIX upgrade

Question

Having an issue with WIX installer upgrade. Previously we had 2 version of installers 1 for per-machine and another for per-user.

Currently we have developed a dual mode

Answer 1

I believe this is occurring because in your installer the default mode is Per-User hence it is not detecting per-machine. You could use MSIGetProductInfo to find the installed products if the assignmenttype is “1” then you could set the below properties to Product Code of Per-Machine product WIX_UPGRADE_DETECTED OLDERVERSIONBEINGUPGRADED

Use a custom action on button click or schedule it after FindRelatedProducts. This tells the installer of an existing version and installation is handle like an upgrade.