Hello You will see the same message on minor upgrade as well, however first you will see the upgrade dialog "The setup will perform an upgrade of" your project name." Do you want to continue? dialog,  Once you click on OK you will see the message downgrade message,  Because since ISpreventdowngrade is mainly added for a major upgrade https://docs.microsoft.com/en-us/windows/win32/msi/preventing-an-old-package-from-installing-over-a-newer-version#:~:text=The%20procedure%20in%20this%20topic,in%20maintenance%20mode%20(reinstallation). I have also attached the sample project for minor upgrade, first install the setup from release1 folder, then install setup.exe from "Minor Upgrade 1.01" folder, then again try to install the release1 setup.exe you can see the warning  pop up "Later version is already installed the setup cannot continue"   ... View more