Using WiX, my install will optionally launch one of my installed program files when it completes. However, when my application is launched by the installer, it is usually not displayed in the foreground of the user's desktop. It's buried under other windows, so it's not immediately clear to the user that the program is running.
I've tried having my program forcibly bring itself to the top when it runs, but that hasn't changed the way it runs when started by the installer.