We use a LiveCycle form, but don't utilize Reader Extensions as all of our internal users should have Adobe Pro installed. However, there are a handful (often new employees or people working from new systems), that either don't have Pro installed yet or have Adobe Reader opening PDFs by default.
Is there any way to either prevent a form from opening in Reader, or determine when a PDF is opened with Reader and display a message? The latter is ideal, as we could direct our users to see IT staff to install Pro.