OS X Yosemite: safe mode
This article has been archived and is no longer updated by Apple.
Safe mode may help you resolve or isolate problems that you’re having with your Mac.
When you start up in safe mode, your Mac prevents some software, such as startup items, from loading, and it performs a check of your startup disk. Your Mac may take longer to start up because of the check.
Last Modified: Jan 22, 2016