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