Startup key combinations for Intel-based Macs

Learn about the startup key combinations you can use with Intel-based Macs.

You can use the following startup key combinations with Intel-based Macs.

Keystroke	Description
Press C during startup	Start up from a bootable CD, DVD, or USB thumb drive (such as OS X install media).
Press D during startup	Start up in Apple Hardware Test (AHT).
Press Option-Command-P-R until you hear startup sound a second time.	Reset NVRAM
Press Option during startup	Start up in Startup Manager, where you can select an OS X volume or network volume to start from.
Press Eject, F12, or hold the mouse or trackpad button	Ejects any removable media, such as an optical disc.
Press N during startup	Attempt to start up from a compatible network server (NetBoot).
Press T during startup	Start up in Target Disk Mode.
Press Shift during startup	Start up in Safe Boot mode and temporarily disable login items.
Press Command-V during startup	Start up in Verbose mode.
Press Command-S during startup	Start up in Single-User mode.
Press Option-N during startup	Start from a NetBoot server using the default boot image.
Press Command-R during startup	Start from the OS X Recovery System1

1 Available on Macs that ship with OS X Lion. Some CPUs require an EFI BootROM update to support this feature.

Additional Information

For the best experience with startup keys, press the keys immediately after the startup tone plays.

Last Modified: Jan 30, 2013