Here we go…
The default solution for installing OS X Mavericks is to download it free from the App Store and then perform an upgrade from a previous version of Mac OS X, whether that’s from Mountain Lion or Snow Leopard. Upgrades are fast, efficient, and most important, very easy, and that’s the recommended option for the vast majority of Mac users. Nonetheless, some users may want to start fresh with a blank slate, using what’s known as a “clean install” and that’s what we’re going to cover here. Performing a clean install can be desirable for a variety of reasons, from ditching years of built-up cruft on older Macs from many years of OS X upgrades, to troubleshooting difficult issues, to transferring ownership of a Mac to a new owner.
How to Clean Install OS X Mavericks