Complete Steps to Perform a Clean OS X Reinstall on Your MacBook Air
From Mac Guides
- This article or section is based on a forum post written by clayj.
This guide is provided in order to make it easier for you to free up valuable hard drive/SSD space on your MacBook Air (MBA) by reinstalling Mac OS X with only the components that you really need. It is recommended that you perform these steps before you install a bunch of applications and data files, because these steps will reset your MacBook Air's hard drive/SSD completely. Performing these steps can free up as much as 8 GB of hard drive space for you to use.
Performing a Clean Install
If you want to perform a Remote Install using another computer's DVD drive (Remote Disc), click here.
If you have a SuperDrive or some other USB-connected external DVD drive, here are the steps to follow to perform a clean install of OS X:
- Insert your Mac OS X DVD #1 into your SuperDrive or other USB-connected external DVD drive.
- Shut down your MacBook Air. Then, turn it back on and hold down the C key to boot from the Mac OS X DVD. The Apple logo will come up and the "processing" indicator will spin for a while.
- The screen will eventually turn blue, and then you will see the nebula wallpaper and be prompted to select a language. Select "Use English for the main language", or select your appropriate language. Then, click the "-->" button. The Mac OS X Leopard Installer window will appear.
- In the Utilities menu, select Disk Utility. The Installer window will disappear and the Disk Utility window will appear.
- Once disk information has been gathered, select your hard drive. This will be the item ABOVE "Macintosh HD". In the case of a 64 GB SSD, the item should be called "55.9 GB MCCOE64GEMPP" or something similar.
- Click Partition. Under Volume Scheme, select "1 Partition". In the Name box, type "Macintosh HD" or whatever you want your hard drive to be named. Then, click Apply. Click Partition to confirm repartitioning of the hard drive/SSD. It will take a few seconds for the drive to be partitioned. Once it's done, quit Disk Utility. The Disk Utility window will disappear and the Installer window will reappear.
IMPORTANT: If you fail to perform steps 4-6, you will not have a clean install, and it is possible that you will not be able to prevent applications from being installed.
- In the Installer window, click Continue. Click Agree to agree to the software license agreement (you can read it first if you really, really want to).
- In the "Select a Destination" window, select your hard drive ("Macintosh HD" or whatever you called it). Click Continue.
- In the Install Summary window, click Customize (lower-left corner of the dialog box).
- In the list of package names, you can turn OFF (uncheck) any or all of the following items, depending on whether you think you will ever need them. Turning off all optional items can free up around 8 GB of disk space for you to use.
- Printer drivers (3.4 GB): You can opt to not install ANY printer drivers by clearing the Printer Drivers checkbox. You can also install just specific printer drivers by turning ON only the checkboxes for those printer drivers you think you might need (Hewlett-Packard, for example).
- Additional fonts (141 MB): This installs font support for Chinese, Korean, Arabic, Hebrew, Thai, Cyrillic (Russian), Devanagari, Gujarati, Punjabi, Tibetan, Armenian, Cherokee, and Inuktitut alphabets. If you want to save 141 MB because you're sure you won't need this, you can turn the Additional Fonts checkbox OFF. However, it is recommended that you install this in case you access web sites that use any of those alphabets.
- Language translations (1.8 GB): If you are only ever going to use one language (English) on your MacBook Air, you can turn this option OFF. Individual languages may be installed by turning ON their checkboxes. Each language is roughly 100 MB in size.
- X11 (117 MB): This option allows you to run Linux and UNIX apps in OS X. You can turn this option OFF if you are sure you will never do this.
- Bundled applications (3 GB): This contains many separate items which you may or may not want to install:
- CPU help files (262 MB): This is the user's manual for the MacBook Air and for Leopard, so this is probably a good thing to install.
- iWeb (290 MB): iWeb is the iLife web design application. If you don't plan to use it, you don't need to install it.
- Garageband (1 GB): You can clear the checkbox for GarageBand if you choose. Note that the "GarageBand Additional Instruments and Loops" option (1.3 GB) is turned OFF by default.
- iDVD (559 MB): You can clear the checkbox for iDVD if you choose; the MacBook Air has no built-in optical drive, so it's likely you will not use iDVD on your MacBook Air. As with GarageBand, the "iDVD Extra Content" option (342 MB) is turned OFF by default.
- iPhoto (553 MB): You can clear the checkbox for iPhoto if you choose.
- iMovie (136 MB): You can clear the checkbox for iMovie if you choose.
- Once you've made the changes you want, click Done. Then, click Install. Click Continue Installation once you verify you have both Mac OS X DVDs.
NOTE: You can click Skip if you want to skip the DVD consistency check. This will save you a lot of time in the installation process.
- When the Installer is done with Mac OS X DVD #1, the MacBook Air will automatically restart and eject OS X DVD #1. When this occurs, go ahead and insert OS X DVD #2; YOU MAY NOT BE EXPLICITLY TOLD TO INSERT THE DVD. Insert the DVD and installation will continue automatically for about 10 to 20 more minutes. When installation is complete, you will be prompted to click Continue.
Mac OS X DVD #2 will be ejected and your MacBook Air will automatically reboot and you will go through the normal first-time experience (selecting language, entering Apple ID, creating user account, etc.). When this process completes, you should see that you now have more free hard drive space available than before.
Using Remote Install
If you want to reinstall OS X using another computer's shared DVD drive (Remote Disc):
- Insert the Mac OS X DVD #1 into the DVD drive of the other computer.
- If the other computer is a Mac, with its software up to date, launch the application /Applications/Utilities/Remote Install Mac OS X from that Mac's hard drive. If it's a PC running Windows, choose "Remote Install Mac OS X" from the Install Assistant when it appears.
- Read the introduction (if you really, really want to) and click Continue.
- Choose the install disc you want to use, and click Continue.
- Choose a network connection: AirPort, if you are using an AirPort/WiFi network, or Ethernet, if the other computer is on an Ethernet network and you have an optional Apple USB Ethernet Adapter connecting your MacBook Air to the same network. Click Continue.
- Restart your MacBook Air and hold down the Option key as it starts up, until you see a list of available startup disks.
IMPORTANT: This step is critical. If you don't hold down the Option key on your MacBook Air until the list of startup disks appears, you may not see the menu. It is recommended that you hold down the Option key until you actually see the OS X Installer appear.
- Click Continue in Remote Install Mac OS X.
- If you chose AirPort as your network in step 5, on your MacBook Air, choose your AirPort/WiFi network from the pop-up list. If the network is secure, you will be prompted for a password. You can enter a private network name by choosing the ellipsis (...) and typing the name.
- If you chose AirPort as your network in step 5, when you see the AirPort status icon indicating signal strength, click Continue in Remote Install Mac OS X.
- Once the OS X Installer begins to run, continue with step 3 in the section Performing a Clean Install.
It is also recommended that you temporarily remove security/passwords from your WiFi network before attempting the Remote Install process.
More Things You Can Remove Manually
You can also free up additional disk space by performing the following:
Delete the "Alex" voice
If you use the Finder to go to /System/Library/Speech/Voices on your hard drive, you can delete the folder "Alex.SpeechVoice". This will free up an additional 670 MB of disk space.
Switch to Hibernate Mode 0
By default, Apple notebooks (including the MacBook Air) ship from the factory in "Hibernate Mode 3", which writes the contents of RAM out to a file called sleepimage on the hard drive just before power runs out completely. This allows the notebook to safely return to its pre-power failure state when power is restored. The size of the sleepimage file is equal to the amount of RAM you have installed in your notebook, so on a MacBook Air, the sleepimage file is 2 GB in size. If you don't mind the risk of what will happen if power fails completely and your programs are not written out to the sleepimage file, you can turn off that feature by switching to Hibernate Mode 0 and reclaim 2 GB of hard drive space. To do this:
- Launch the Terminal application (Applications > Utilities).
- At the prompt, type pmset -g | grep hibernatemode and press Return. (NOTE: The "|" is a pipe symbol, the character above the "\" symbol on your keyboard. This is NOT a lower-case "L" or upper-case "i"!) You will see your current Hibernate Mode setting.
- To change to mode 0, type sudo pmset -a hibernatemode 0 and press Return.
- To remove the sleepimage file, type sudo rm /var/vm/sleepimage and press Return.
Note that at any time, you can return to Hibernate Mode 3 by typing sudo pmset -a hibernatemode 3 and pressing Return in the Terminal window. This will automatically recreate the 2 GB sleepimage file.
Readding Components Later On
If later on you want to install something you chose not to install using the above steps, you can insert the Mac OS X DVD #1 into your DVD drive (SuperDrive or shared Remote Disc) and then double-click Optional Installs > Install Bundled Software Only > Continue > Continue > Customize. This will let you (re)install the CPU Help Files, iWeb, GarageBand, iDVD, iPhoto, and iMovie.