Please note that you can run the related .EXE after a post-install prerequisite. Just make sure you schedule the custom action that launch the .EXE file after the Finish Execution stage from the Wizard Dialogs Stage.
I have already tried this, this works without issues when NOT doing silent install, issue with silent install is that Finish Execution stage is triggered even before post-install prerequisite installation is completed. I even tried adding custom action to run exe AFTER InstallFinalize stage and still same issue
And also is there a way to only run the prerequisite on silent install?
I'm not sure I fully understand your scenario. Can you please give us more details?
Ok, I'll explain. I only want to run exe WHEN doing silent install, so yes I can run related EXE after a post install so now how do I know that installer is running on silent install? again I need to know this because I only want to run exe WHEN doing silent install. And one more thing related to this, how can I run exe found in install path as prerequisite? - All of these can be done using custom action but there is also issue with custom action as I mentioned in previous paragraph