Learn About Startup Key Sequences for Intel Macs [OS X Tips]



The keyboard on your Intel based Mac is a powerful tool even before Mac OS X Lion launches. You can use it to do a variety of things like selecting the media or startup drive to boot your Mac with, launching diagnostics, or performing resets that might help resolve problems with your Mac.

Select An Alternative Startup Disk

If you press and hold C after turning your Mac on it will start from a bootable CD or DVD, such as the Mac OS X Install DVD or USB stick that came with the computer.

If you have multiple startup disks attached to your Mac or perhaps a disk partitioned with multiple bootable partitions simply press and hold the Option key while starting your Mac. You’ll be presented with the Mac OS X volumes you can start from. Just select the one you want with the arrow keys and press Enter to startup your Mac from that drive or volume. Bonus: if you press and hold the N key you’ll also see the first available Network volume in the list.

Start Your Mac Using Netboot

As an alternative to the startup key sequences above you can simple press and hold N as your Mac starts to startup from a compatible network server on your local network using Netboot.

Perform a Mac Hardware Test

If you need to do a hardware test you can press and hold D after starting your Mac to launch the Apple Hardware Test.


If you are instructed to do a NVRAM or PRAM reset press and hold Option-Command-P-R until you hear your Mac make the start-up chime twice.

Force Eject Optical or Removable Media

Now here’s a good one when you have optical media in your optical drive or if you have problems ejecting the media. Restart your Mac and press and hold Eject, F12, or hold the mouse or trackpad button. Any of these actions will cause your Mac to eject any removable media that might be inserted. Especially a CD or DVD.

Start Your Mac in Target Disk Mode

Pressing and loading the T key during startup forces your Mac into Target Disk Mode. Target Disk Mode turns your computer into an external disk drive or at least it acts like one. You’ll have full access to the startup disk on that computer via FireWire or Thunderbolt unless you’ve secured your drive like I showed you how to do earlier.

Start Your Mac in Safe Mode

Here’s a handy key sequence to know if you need to troubleshoot Mac OS X problems or problems with apps on your Mac. If you press and hold the Shift key during startup your Mac starts in Safe Mode and that will temporarily disable all login items associated with your Mac and your user account.

Verbose Startup Mode

If you are an experienced Mac OS X or Unix user you’ll find Command+V for Verbose startup mode to be handy for troubleshooting startup issues. While in this mode you’ll see things you wouldn’t normally see while your Mac starts.

Single User  Startup Mode

Experienced Mac OS X or Unix users will find the ability to start their Mac in Single-User mode using Command+S to be handy for advanced startup sequence troubleshooting. You’ll need to know a bit about Unix commands to make Single-User mode really useful.

Start Lion HD Recovery

Finally, if you are using Mac OS X Lion you can press Command+R during startup to start the Lion Recovery utilities.

Do you know any other useful startup key sequences? How about sharing yours by leaving a comment.

  • Justin Tran

    Hi David W. M,
    This is a great article! Do you have it in Cult of Mac video version? I would love to see in youtube version and always know that it’s there tor future references.

  • dcj001

    If you save this page as a PDF, you’ll always have it as a reference.

  • Jdsonice

    Is there any advantage of resetting the NVRAM/PRAM on a regular basis? I was told that one should consider resetting the PRAM to speed up the mac. Is there any basis for this?


  • Wagner Rosa

    Holding down the option key at the startup you can choose which HD do you want to use (your own Mac OS X partition or Recovery partition). I’ve used this and it’s really handful when you got the “infinite loading” gray screen. 

  • Justin Tran

    Great! Thanks

  • prof_peabody

    Resetting the PRAM used to fix a lot of things but mostly nowadays it isn’t needed at all. 

    So if you have an older mac and it won’t start it’s worth a try to reset the PRAM as it can miraculously resuscitate an older computer sometimes, but it’s not necessary to do it all the time.  

    It would be more worthwhile to get in the habit of making sure you turn the mac off once in a while, as well as leave it on overnight once in a while, so all the various daemons can run.

  • dcj001

    And, if you’d like Apple’s list, you can go here:


  • Bilal S. Sayed Ahmad

    One big one for Macs with latest EFI is holding Option+Command+R.  This starts Internet recovery from Apple’s Servers rather than your HDD.  This is useful for anybody changing their HDD out.

  • G Funkdafied

    Keep in mind that if you’ve ever done an erase and install, you’ve also deleted the the Apple Hardware Test so holding D while booting won’t do anything.

  • Patricio Benavente

    Apple Support – Startup key combinations for Intel-based Macs