To boot your Intel-based Mac into any of OS X’s built-in startup modes, you must press and hold one or more keys detailed below after turning on the computer. Press the keys immediately after hearing the startup sound, unless otherwise specified.
- Manually restart: Power (⎋)
- Boot from CD/DVD: C
- Startup Manager: Option (⌥)
- Single-User Mode: Command (⌘)—S
- Target Disk Mode: T
- Verbose Mode: Command (⌘)—V
- Safe Mode: Shift (⇧)
- Recovery OS: Command (⌘)—R
- Internet Recovery OS: Command (⌘)—Option (⌥)—R
- Apple Hardware Test: D
- Apple Hardware Test over the Internet: Option (⌥)—D
- Boot from NetBoot server: N
- Boot from NetBoot server using the default image: Option (⌥)—N
- Eject removable media: Media Eject, F12, mouse button or trackpad button
- OS X Startup Volume: X will start up your Mac from an OS X startup volume when it’d otherwise boot from a non-OS X volume, like a Windows partition
- Prevent Login Items from opening: To override your current settings and prevent Login Items and Finder windows from your last session from opening when you log in, hold down the Shift (⇧) key after clicking the Log In button in OS X’s login window until the desktop appears.
- Prevent automatic login: If you enabled the option to automatically log a specific OS X account every time your Mac starts up, you can override this setting by holding the left Shift (⇧) key after OS X’s boot progress indicator appears.
- Reset PRAM/NVRAM: Command (⌘)—Option (⌥)—P—R, then release the keys after you hear the startup sound for a second time
- Reset SMC: Shut down your Mac, and then press and hold the left-side Shift (⇧)—Control (⌃)—Option keys along with the Power (⎋) button, all at the same time, until the computer turns on. Now release the keys and then turn your Mac back on using the power button.