When making installers it's important to make it possible to run the installer silently. This is a requirement if you want to include your installer in another installer. I've inherited some installers on my new job, these were made in Nullsoft Scriptable Install System (NSIS). We have a requirement to include several application installers into a package to make the installation easier for the end users, so I've looked into what needs to be done in NSIS to make the installers silent.
It turns out to be quite easy, see the chapter on silent installer/uninstaller in the documentation, all MessageBoxes in the script has the possibility to have a /SD parameter where you can set the default return value if the installer is running in silent mode /S. To reduce cluttering the start menu with uninstaller links it's possible to use the IfSilent statement to jump over the creation of uninstall links.