Performing a Clean Install of OS X Mavericks (Update)

OS X Mavericks is officially out and available to the public. This is Apple’s latest version of OS X and comes with a host of new features, including enhanced support for multiple displays, desktop versions of Maps and iBooks, an improved Safari browser, and much more. It is now available for free on the Mac App Store.

While most users will appreciate the easy upgrade process OS X has, some users prefer to start from scratch with a clean OS installation when upgrading to a new version. A fresh clean install means that your computer’s hard drive has been completely wiped and OS X Mavericks has been restored to factory settings. This means that no applications are installed and no files are stored; default apps and files that only ship with OS X Mavericks.

Personally, I always do a clean install. There are just too many problems when upgrading and I have so many files that they can get erratic and cause unnecessary slowdowns during the upgrade. Basically, when you do a simple upgrade, the new OS is installed and then the installer takes all the old files and throws them over the newly installed OS, which can easily cause problems.

However, here’s how you can install a fresh copy of OS X Mavericks and start with a clean slate. Be warned though: to perform a clean install of OS X, you must create a bootable installation drive using a USB flash drive. You’ll be moving a bunch of files and messing with Terminal. If this isn’t something you’re afraid to do on your own, we recommend upgrading or finding a friend who can do a clean install for you.

Preparing for a Clean Install

First, you’ll want to make sure OS X Mavericks is supported by your Mac. Some Macs dating back to 2007 support OS X Mavericks, but for a complete list of supported Mac models, check out this list.

You’ll also want to back up everything before starting the clean install. You can use Time Machine to easily back up all your files to an external hard drive, or you can manually select the files you want to keep and transfer them to an external hard drive or USB flash drive.

Next, Download OS X Mavericks from the Mac App Store. It will automatically download and save to the folder. It can also automatically start the installation process after the download is finished. If this happens, cancel immediately.

Making a Bootable USB Drive

To install a clean fresh copy of OS X Mavericks, you must create a bootable installation drive using a DVD, USB flash drive, or external hard drive. We’re going to use a USB flash drive for this tutorial, since not everyone has an optical drive in their Mac, and you probably have a USB flash drive too. Make sure it is at least 8GB in size.

Reader Jason pointed out a faster method to create a USB boot drive for OS X Mavericks. Watch below, especially if our first method doesn’t work for you.

1. Plug in your USB drive and turn it on.
2. Select the USB drive from the sidebar and click the tab.
3. Select it in the Format box and name it.
4. Click it and wait for the format to finish.
5. Once complete, close Disk Utility and save the . Type and press the following command:

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

This command will officially make the USB boot drive and will take about 20 minutes. Don’t mess with the Terminal or remove the flash drive while it’s doing its job. When it’s done, it will tell.

Then go to the section in this guide to complete the setup.

Follow these steps to successfully create your OS X Mavericks USB boot disk.

1. Plug in your USB flash drive and turn it on.
2. Click on USB drive from the left side menu.
3. Click the tab.
4. Choose from the drop-down menu.
5. Click the button and select it as the partition type.
6. Click to close this window and then . This will format the USB flash drive and prepare it for OS X Mavericks.

Next, you’ll want to launch Terminal as you’ll be entering a few commands to show hidden files in the Finder (you’ll then navigate through some hidden files). Enter these two commands as shown below and press Enter after each one. After entering these, you can exit Terminal.

1. defaults com.apple.Finder AppleShowAllFiles writes TRUE
   
2. killall Finder

After creating the USB boot drive, it should look like this.

Hidden files are now viewable in Finder and appear a bit dimmed. After entering these two commands, you can exit Terminal. But this is only the beginning of making the bootable USB installation drive.

1. Open it from Finder and open the folder. Find the tagged file.
2. Right click on it and select it. A new folder window will appear.
3. Select and open.
4. double click on it. This should open another folder window. If not, click it in the Finder sidebar.
5. Once inside that, double click on it. (BaseSystem.dmg is a hidden file, so we put these Terminal commands earlier). If not double click, right click on it and select.
6. Open it again and select from the sidebar. Click the tab.
7. Then, when set to, drag the USB drive to the Destination box to set it to USB drive.
8. Click to start the process and confirm that the driver contents will be completely erased. This process will take 5-10 minutes.

Unfortunately, I wish that was all, but you’ll need to do a few more things to get your bootable USB installation drive ready for use; You’re still on the farm!

Once the restore is finished, open Finder and navigate to the newly created USB drive and navigate to the tagged file. Keep this window open though, because you’ll be back in this window and replacing the file you just deleted with a folder called “Packages”.

Go back to the linked image and drag and drop the folder into the same folder where you just deleted the file. Be sure to copy and not cut and paste. It’s a big folder, so it will take some time. However, once the copy is complete, the bootable USB installation drive is made and ready to use! I hope it goes smoothly from here.

Installing OS X Mavericks

Now that you have a bootable USB stick with OS X Mavericks on it, it’s time to install it. With the USB drive connected, restart your Mac and hold down Option/Alt. This will bring up a menu where you will select an install driver. Select the USB drive you just created (in this case it’s usually called and is orange). Click the up arrow under the drive icon to get started.

Now, before installing Mavericks, you will want to erase and reformat your hard drive, so on the “Install OS X” screen, navigate to the top menu bar and click on it.

1. Then click on your main hard drive in the sidebar on the left.
2. Click the tab and make sure it is selected in the field.
3. Give the hard drive a name. If you want to stick to the Mac naming convention, you can use the .
4. Click in the lower right corner to start the deletion process.
5. Once this is done close Disk Utility where you will be brought back to the “Install OS X” screen.
6. Click and follow the given steps to start the OS X Mavericks installation process.
7. Enjoy OS X Mavericks!

This is a rather complicated method of creating a bootable installation drive, but we anticipate that after Mavericks is out for a few months, third-party tools will be released to facilitate the creation process, similar to that of the operating system. X Mountain Lion tools that easily creates a USB install drive for you. But for now, this seems to be the only way that works.