Note: Startup will likely take substantially longer than normal.Once the gray Apple and progress indicator appear, release the Shift key.Immediately after the startup chime, press and hold the Shift key.10.4 or later: Disables all startup and login itemsĪ Safe Boot can potentially repair problems that prevent Mac OS X from starting properly.10.3.9 or earlier: Disables all non-Apple startup items.Load only the required kernel extensions.Force a directory check of the startup volume (as Disk Utility's Disk Repair).This can help to troubleshoot startup problems when an OS installation disc is not available.Ī Safe Boot will perform the following tasks: This document explains how to perform a Safe Boot in Mac OS X 10.2 or later and how to boot into the recovery partition for OS X Lion.