I purchased a MacBook Air from someone 4 months ago and everything was working perfectly. There is no user name or password needed to log in and I've never had problems using it.

Now I would like to reinstall OS X but I can't do it because it's asking for a firmware password when booting with Option ⌥ held down. It's 4 months now and I've lost the seller's phone number to ask for password.

I've tried to reset NVRM but those keys are disabled. I can't boot from external HD when I turn on the system. What is the reset procedure?


5 Answers 5


To reset the firmware password it looks like you have to take it in for service at your nearest Apple Support location as noted in the following Apple Support Article MacBook Air (Late 2010) and later, MacBook Pro (Early 2011) and later, iMac (Mid 2011) and later, Mac mini (Mid 2011): Recovering a lost firmware password


Learn what to do if you no longer remember the firmware password that you've set or if you see a password dialog when you try to select a startup volume on a MacBook Air (Late 2010) and later, MacBook Pro (Early 2011) and later, iMac (Mid 2011) and later, or Mac mini (Mid 2011) computer.


Only Apple retail stores or Apple Authorized Service Providers can unlock these computers protected by a firmware password.

If you cannot remember the firmware password for your Mac, schedule a service appointment with either an Apple Retail Store or an Apple Authorized Service Provider. If you plan to visit an Apple Retail store, please make a reservation at the Genius Bar using http://www.apple.com/retail/geniusbar/ (available in some countries only).

As a side note you will need the original proof of purchase.


The only way to reset the open firmware password is to take the Air to an Apple store or other authorised Mac reseller.

see: How do Apple engineers reset EFI password on new MacBooks?


This workaround is applied to my MacBook Pro 2018 Intel chip.

You could try the following commands on the terminal to find a solution to your problem. However, I want to emphasize the importance of disabling the firmware password so that you can access any start-up items such as Recovery Mode, Internet Recovery Mode, Safe Mode, and so on without being forced to input a forgotten or lost firmware password.

# delete password; laptop restart needed
sudo firmwarepasswd -delete

Before erasing the firmware password, you can enable Terminal in Settings > Privacy & Security > Full Disk Access and disable FileVault. After deleting or disabling the firmware password and after restarting, revert back to the original settings.

Enabling firmware passwords can be a beneficial practice for some, but what if you forget your firmware password? How can you retrieve it? What if your device does not permit Mac device repair or you don't want to set an appointment with an Apple Service Center? What if you don't want someone to open your device's logic board? It is somewhat tough and time-consuming to recover the firmware password.

If you like to set a firmware password for security reasons do the following but be sure to securely save the password elsewhere for easy retrieval because you will be prompted now to enter the firmware password on any start-up recovery modes if the password is set.

# set a new firmware password
sudo firmwarepasswd -setpasswd

# check if firmware password is set
sudo firmwarepasswd -check

# verify the firmware password
sudo firmwarepasswd -verify


If you are ALREADY LOGGED IN AS ADMINISTRATOR FROM WITHIN OSX (meaning, that the computer boots to OSX normally, but you get a firmware lock dialogue when trying any EFI startup hotkeys, which is usually always the case in the Airs I've unlocked for folks) you can spotlight "Startup Disk" or navigate to it from Settings.app and you can CHANGE THE STARTUP DISK FROM WITHIN OSX. I apologize if I was not clear or concise enough with my previous post; hopefully this clarifies the instructions.

You will have to trust me on this one, I've done it before many, many times. (unfortunately)

  • Please edit your previous answer instead of posting a new one
    – grg
    Commented Feb 17, 2014 at 21:06

Don't reset it. If you have admin access to the computer's OS X install, just change the startup volume to an external USB with the full OS X installer on it. Mavericks is free from the App Store and you just need to download the installer, mount it or show package contents, copy the .dmg file to desktop, burn it to a USB stick in Disk Utility. It's a simple process. Then start disk.app and change to the USB, then reinstall OS X.

After you reinstall, open Terminal and write a shell command to use the Unix setregproptool (it's inside the firmware password utility.app contents located in the installer image and also on the recovery partition) and remove the password by calling the remove password command. The program will ask for the previous password over and over until you get it right, without any delay. So, you can easily brute force it. Most likely its a 4-digit pin, 6-digit pin, or 4-8 character password. If it was locked from iOS, (app or online) it's 4-digits. If it was locked from a computer or non-Apple mobile device, it's a 6-digit pin, and if it was locked manually, it is a password. I believe it's 12 characters max, but don't quote me on it. Should only take a couple of days at most.

  • You still need the password to boot from the USB! Commented Nov 13, 2013 at 23:34

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