Callender said:
Use Revo then. I find Revo's rules problematic. Geek does reg scan. I also have an app that runs as a service and monitors uninstalls and detects leftovers including registry.

Maybe I should have phrased the original comment better:

Use a decent uninstaller program - not the one built into windows and make sure that you shut down any of the PDF program's running processes or services first.
No biggie. I like Revo. Used it for really deep uninstalls like printer software/firmware. I may try Geek just to see how it works. After all, being a Windows Insider, it seems that I'm "trying" something all of the time. Good deal....