How to stop applications opening on login?
From my own answer at Super User…
If it is not in the regular user Login list, then it is most likely in LaunchDaemons.
There are several locations for these, one is for Apple daemons only:
/System/Library/LaunchDaemons
The others are to include 3rd party processes, /Library/LaunchDaemons and ~/Library/LaunchDaemons.
You may also need to remove from /Library/LaunchAgents or ~/Library/LaunchAgents
Simply remove or zip the process you don't wish to auto-launch &amp; it should be gone at next boot.