"Why do some apps randomly open? when you reboot or start up your Mac?: Every time when I reboot my Mac, or shut it down. when it opens, some apps that I downloaded randomly open with no reason even though I did not turn on re-open applications, I have to reboot something like that."
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Randomly Opening Apps:
What do you mean by "random"? Is this intermittent? Is it only for specific apps? Is it the same at every login.
A. View Login Items:
See if any of these apps are Login Items. IF so, and you do not need them, then remove them from the list.
- Go To: System Settings
- Select: General
- Click: Login Items & Extensions
- Rid of: Items that are Not Needed (Select the item, and then click the "-" button)
B. Pending Items:
You might have pending items, such as downloads and installations that were stopped when you last shut down your Mac. Or, it may be scans that you have scheduled required. If so, they may be popping back up.