A clean install of OS X Mavericks lets you start over from scratch, either by erasing all the data on your startup drive and then installing OS X Mavericks, or by installing Mavericks to a non-boot drive—that is, a drive that doesn’t contain the operating system. Here’s how to perform a clean install of OS X Mavericks—all you’ll need is a USB flash drive.
How to Perform a Clean Install of OS X Mavericks from USB
The OS X Installer can perform both an upgrade installation (the default) and a clean installation to a non-boot drive. However, when it comes to performing a clean install of Mavericks to a boot drive, the process is a bit more tricky.
Unlike older versions of OS X that were distributed on optical media, downloaded versions of OS X do not offer a bootable installer. Instead, you run the installer app directly on your Mac running the older version of OS X.
This works fine for the upgrade installation and the installation without a boot disk, but it does not allow you to erase the boot disk. This is a necessary process if you want to perform a clean installation.
