>So you're saying you just want it to run without the option to decline?

Yes. In most cases that I have seen, the post setup execuatable does some processing that either can't be done with the installation package or is so difficult as to make it more cost effective to do it another way. In either case, the processing done in the file is required for the installation to be considered complete. If the user simply opts out of it, the installation isn't really complete. However, because the installation package believes the functionality you are tapping in to for this to be optional, it goes on as if nothing bad has happened.