turn on your Mac and hold the Command and R keys, simultaneously, immediately after you hear the start-up chime.
Keep hold of them! Within around 10–15 seconds, you will be shown the OS X Utilities options.
OSX Utilities > Disk Utility
For OS X versions preceding and including OS X 10.6 Snow Leopard, you will require either the grey OS X installation DVD that shipped with your Mac, or the retail DVD of an appropriate version of OS X for your Mac.
For Snow Leopard, or earlier, insert the appropriate DVD then press and hold the C key immediately after the start-up chime. The computer will start up using the install media. Alternatively, press and hold the Option key (sometimes marked ALT) at start-up to select the volume containing the installer.
Dealing With Partitions
If you have more than one partition, on the hard drive, you may wish to remove these and return the hard drive to a single partition, first.
From OS X Utilities, select Disk Utility. Select your Mac’s hard drive in the lefthand column, to reveal more options, then select the Partition button.
Examining Partitions in Disk Utility
In the Partition Layout dropdown menu, select 1 Partition.
Create a single partition
In the Partition Information box, enter an appropriate name for your Mac’s hard drive. I’ve chosen Macintosh HD.
Give the Partition a name
Now click Apply. A dialogue box will pop up to confirm the actions you are taking. If you are happy with this, click Partition.
Confirmation of changes to partitions
Erasure and Security
In Disk Utility, of OS X Utilities, select the partition (in the lefthand column) that you created in the previous step.
Preparing to erase
Select Erase and ensure that the Format is Mac OS Extended (Journaled). It should default to this option.
Select the appropriate level of security / speed for deleting your data and click OK then Erase.
Reinstallation of OS X
Reinstall OS X
Following the erasing of your Mac’s hard drive, you are returned to the OS X Utilities options. From this you can select one of two options in order to restore the operating system:
If you prefer to install the operating system afresh, select the second option.
Tip: If you attempt to reinstall OS X onto an existing partition without first erasing it, OS X will reinstall the operating system files and your user files will remain intact. If you wish to remove your data, you must erase the hard drive first.
In this case, reboot your Mac and hold down Command and R immediately following the start-up chime. Your Mac will then try to connect to the internet so that it can download the OS X Utilities back to the hard drive.
Starting Internet Recovery
In the case of operating systems including and preceding OS X 10.6 Snow Leopard, you will need to have either the grey install DVD that shipped with your Mac or an appropriate OS X retail DVD in which to boot from. In this case, reboot and hold down C immediately following the start-up chime.
Advertisement
Factory Fresh Finish
If you are selling, or passing on your Mac to a friend or family member, it is a really nice touch to have the Mac ready to boot into the OS X set up for the first time just like it did when you bought it.
Following the downloading and installation of OS X, simply close down your Mac. The next time it is booted up, it will go straight into the set up routine and ask the new user for their AppleID(s) in order to set up the Mac for their use.
Reboot just like it's the first time!
Keep hold of them! Within around 10–15 seconds, you will be shown the OS X Utilities options.
OSX Utilities > Disk Utility
For OS X versions preceding and including OS X 10.6 Snow Leopard, you will require either the grey OS X installation DVD that shipped with your Mac, or the retail DVD of an appropriate version of OS X for your Mac.
For Snow Leopard, or earlier, insert the appropriate DVD then press and hold the C key immediately after the start-up chime. The computer will start up using the install media. Alternatively, press and hold the Option key (sometimes marked ALT) at start-up to select the volume containing the installer.
Dealing With Partitions
If you have more than one partition, on the hard drive, you may wish to remove these and return the hard drive to a single partition, first.
From OS X Utilities, select Disk Utility. Select your Mac’s hard drive in the lefthand column, to reveal more options, then select the Partition button.
Examining Partitions in Disk Utility
In the Partition Layout dropdown menu, select 1 Partition.
Create a single partition
In the Partition Information box, enter an appropriate name for your Mac’s hard drive. I’ve chosen Macintosh HD.
Give the Partition a name
Now click Apply. A dialogue box will pop up to confirm the actions you are taking. If you are happy with this, click Partition.
Confirmation of changes to partitions
Erasure and Security
In Disk Utility, of OS X Utilities, select the partition (in the lefthand column) that you created in the previous step.
Preparing to erase
Select Erase and ensure that the Format is Mac OS Extended (Journaled). It should default to this option.
Select the appropriate level of security / speed for deleting your data and click OK then Erase.
Reinstallation of OS X
Reinstall OS X
Following the erasing of your Mac’s hard drive, you are returned to the OS X Utilities options. From this you can select one of two options in order to restore the operating system:
- Restore from a Time Machine Backup
- Reinstall OS X
If you prefer to install the operating system afresh, select the second option.
Tip: If you attempt to reinstall OS X onto an existing partition without first erasing it, OS X will reinstall the operating system files and your user files will remain intact. If you wish to remove your data, you must erase the hard drive first.
In this case, reboot your Mac and hold down Command and R immediately following the start-up chime. Your Mac will then try to connect to the internet so that it can download the OS X Utilities back to the hard drive.
Starting Internet Recovery
In the case of operating systems including and preceding OS X 10.6 Snow Leopard, you will need to have either the grey install DVD that shipped with your Mac or an appropriate OS X retail DVD in which to boot from. In this case, reboot and hold down C immediately following the start-up chime.
Advertisement
Factory Fresh Finish
If you are selling, or passing on your Mac to a friend or family member, it is a really nice touch to have the Mac ready to boot into the OS X set up for the first time just like it did when you bought it.
Following the downloading and installation of OS X, simply close down your Mac. The next time it is booted up, it will go straight into the set up routine and ask the new user for their AppleID(s) in order to set up the Mac for their use.
Reboot just like it's the first time!
