What's the best way to restore a Mac without a recovery partition?

In the event of a serious problem, you may need to reinstall your whole Mac operating system using the recovery partition. But how do you restore a Mac that's missing a recovery partition?

It is possible to restore a Mac without a recovery partition, but it can be tricky (especially on older Macs). You have two approaches available:

  • Use Internet Recovery to reinstall OS X on Mac with a missing recovery partition.
  • Create a OS X installation drive from an old USB Thumb Drive and reinstall OS X.

We're going to look at both of these options in this feature - but first, a quick explanation of what a recovery partition is.

Read next: How to create a Mac recovery partition in El Capitan and Yosemite

How to restore a Mac without a recovery partition: What is the OS X recovery partition? (And what are partitions in general?)

Most people don't really think about hard drives in terms of partitions (and volumes). They just see the whole drive as one thing.

A hard is typically a single volume, but it is then split up into multiple areas, known as "partitions". Think of your hard drive as the house, and the partitions as different rooms.

You're used to only seeing one room in the house, the one which has your Desktop, Folders and Applications. But there are four partitions, and one is used in extreme cases where you may want to completely reinstall OS X. Even if you completely wipe OS X, and start again from scratch, the recovery partition will be there to step in and reinstall OS X.

It's a problem if the recovery partition is missing. After all, how do you go about reinstalling OS X from scratch? It does happen: if you've placed a new hard drive in your Mac, or accidentally wiped the recovery partition by installing Windows, Linux or another OS on your Mac, then you may not have the recovery partition to work with.

How to restore a Mac without a recovery partition: How to check if your Recovery Partition is working

How to restore a Mac without a recovery partition: The recovery partition

First you should check that your Mac definitely hasn't got a working recovery partition. It used to be that holding down the Option key in OS X would bring up the Startup Disks (including the recovery partition). But now it only displays the OS X system disks (typically just your main hard drive).

Here is how to boot into Recovery Drive:

  1. Shut down your Mac. (Apple menu > Shut Down.)
  2. Hold down the Command and R keys simultaneously and press the Power button.
  3. Keep holding Command and R until the Apple logo appears on the screen. Let go of the keys and wait for the Mac to complete starting up. (It should take longer than normal.)
  4. You should be faced with a screen saying OS X Utilities. This is the Recovery Partition. If you have this, stop worrying. You're good to go.

If the Mac boots into OS X, or if you're faced with a completely blank screen, then you haven't got a recovery partition. If your Mac does boot into OS X then you can also check Terminal to see if you have a recovery partition:

  1. Open Terminal.
  2. Enter diskutil list.

You should see a list of all the volumes and partitions on your computer. The first drive (/dev/disk0) should have a partition (typically listed as "3" with Apple_Boot Recovery HD after it). Try using the Command-R process again. Before you move on to reinstalling OS X, try a few of these tips:

  • Reset your PRAM. Shut down your Mac and hold down Command-Option-P-R during boot. Wait for the chimes and let go.
  • Check your keyboard (especially if it's a Bluetooth keyboard). Try using a wired keyboard if possible.

Okay, so either your Recovery Partition is missing, or doesn't work and you've tried everything. So it's time to look at reinstalling OS X. First you should take time to back up up OS X if you can using Time Machine. This will enable you to restore all your files, folders and apps once you've reinstalled OS X.

How to restore a Mac without a recovery partition: Use Internet Recovery to reinstall OS X

How to restore a Mac without a recovery partition: Internet recovery

If you haven't got a recovery partition on your Mac, then you need to reinstall OS X. Even if OS X is working, you should probably consider reinstalling it because a missing Recovery Partition is not a good sign. But mostly you'll be confronted with this problem when OS X isn't working and you can't recover it the normal way.

The first approach is to use a feature called Internet Recovery. Newer Macs are able to boot directly from an internet connection, even with no recovery drive available. Here is how to use OS X Internet Recovery:

  1. Shut down your Mac.
  2. Hold down Command-Option-R and press the Power button.
  3. Hold down the keys until you a spinning globe and the message "Starting Internet Recovery. This may take a while".
  4. The message will be replaced with a progress bar. Wait for it to fill.
  5. Wait for OS X Utilities to appear.
  6. Click Reinstall OS X and follow the installation process.

There are issues with Internet Recovery. It only works with networks using WEP and WPA security. This is most home Wi-Fi networks, but if you're on a proxy network or PPPoE then you will have problems. In these cases it's usually best to find another network rather than create a USB Recovery Stick (our next step). If you have Internet Recovery, then make use of it to reinstall OS X if possible.

How to restore a Mac without a recovery partition: Create a OS X bootable installer from a USB flash drive

How to restore a Mac without a recovery partition: Download El Capitan

If you don't have Internet Recovery, then you are left with the final option. This is to create a bootable installer from a USB flash drive (at least 8GB in size). Note that this completely erases the USB flash drive, so be careful to remove any files from it first.

There are two ways to create a USB flash installer. One is to use Terminal, the second is to use an app called DiskMaker X. Here's the Terminal approach.

Open the Applications folder and check for Install OS X El Capitan. If it isn't present, open App Store and click Purchased, then click Download next to El Capitan. Wait for the file to fully download.

1. Attach your USB flash drive.

2. Open Disk Utility.

3. Select the volume (under External) in the sidebar. The Volume is the top part, not the partition (which is underneath).

4. Click Erase.

5. Make sure it says "Untitled" in the Name field. Don't change this. Click Erase.

6. Open Terminal.

7. Cut and paste the following line into Terminal:

sudo /Applications/Install\ OS\ X\ El\ Capitan.app/Contents/Resources/createinstallmedia --volume /Volumes/Untitled/ --applicationpath /Applications/Install\ OS\ X\ El\ Capitan.app/

You'll need to enter your admin password. And then enter "y" and press Return. It will first wipe your flash drive, then turn it into a bootable installer.

How to restore a Mac without a recovery partition: Create installer media

8. Wait for the process to completely finish.

If this process is a bit daunting, then consider downloading DiskMaker X. This program automates the process of building an OS X installer

How to restore a Mac without a recovery partition: How to use a OS X bootable installer

Then follow these steps to use the bootable installer:

  1. Make sure the OS X bootable installer (USB flash drive) is connected.
  2. Shut down your Mac.
  3. Hold down Option and press the Power button.
  4. The startup device list window should appear displaying a yellow drive with Install OS X El Capitan below it.
  5. Select it and press Return. Wait for the progress bar to fill.
  6. Select Disk Utility.
  7. Select the drive under Internal (your main hard drive).
  8. Click Erase.
  9. Give the drive a name; "Macintosh HD" is traditional but you can choose. Ensure that the Format is OS X Extended (Journaled) and the Scheme is GUID Partition Map.
  10. Click Erase.
  11. Click Done.
  12. Choose Disk Utility > Quit Disk Utility.
  13. Select Install OS X and click Continue.
  14. Follow the install OS X options.
  15. Select Macintosh HD as the installation disk, when presented, and click Install.

OS X will now be installed on your hard drive from the OS X bootable installer. The whole process can take around half an hour. After this has finished you will have a blank installation of OS X along with a new recovery partition.

You may get the message: "This copy of the Install OS X El Capitan application can't be verified. It may have been corrupted or tampered with during downloading." If so you need to adjust the date and time in OS X. Follow the information in this AskDifferent StackExchange page.