How do I stop programs from opening in start up?
Go to System Preferences -->Users & Group, select your users and Login Items, selected the program you don't want and click the "-" (minus sign).
And if scooterFrank's advice doesn't work, post here again. There are other methods of launching apps at startup, but this is what you should check first.
I have the same issue. Office for window is loading on start up and I do not want it to. I have no Login Items on my user preference.
Put them in the dock, right click (control-click) on them, hover your mouse over Options, and un-check Open At Login.
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