A&A IT Troubleshooting Articles & Additional Resources

Hold during startup

Description

Shift (⇧)

Start up in Safe Mode.

Option (⌥)

Start up to Startup Manager, which allows you to choose other startup disks, if available.

C

Start up from an available CD, DVD, or USB thumb drive that contains a valid operating system for your Mac. Or use Startup Manager, as described above.

D

Start up from the built-in Apple Hardware Test or Apple Diagnosticsutility, depending on your Mac model. Or use Option-D to start up from this utility over the Internet.

N

Start up from a compatible NetBoot server, if available. To use the default boot image on the NetBoot server, hold down Option-N instead.

Option-Command (⌘)-P-R

Reset NVRAM or PRAM.

Command-R

Start up from the built-in macOS Recovery system. Or use Option-Command-R or Shift-Option-Command-R to start up from macOS Recovery over the Internet. macOS Recovery installs different versions of macOS depending on the key combination you use while starting up.

Command-S

Start up in single-user mode.

T

Start up in target disk mode.

X

Start up from your macOS startup disk when your Mac would otherwise start up from a non-macOS startup disk, such as a Windows partition. Or use Startup Manager, as described above.

Command-V

Start up in verbose mode.

Eject (⏏), F12, mouse button, or trackpad button

Eject removable media, such as an optical disc.