You can go to System Preferences > Accounts, then click on the "StartUp" tab, select "Safari" and click on the "-" (minus button) to remove it from the list of applications that will run at startup.
How Do I Stop Safari From Opening At Start Up? Someone Somehow Fixed This For W And Now I Need It To Stop.
You go to options and deselect the box which says run at startup.
To stop safari from popping up click on the right side of the mouse and their is a point mark on open at login. Click on it.
their you got it off