How to Clean Install OS X Yosemite
Most Mac users who are upgrading to OS X Yosemite should go through the standard process via the Mac App Store and start the installation from there, it’s by far the easiest approach and it generally goes flawlessly. Some users like to perform what is known as a clean installation of Mac OS X though, which is essentially wiping the Mac drive, and starting fresh with a brand new untouched install of OS X Yosemite, and then manually copying or accessing files and re-installing apps. While clean installing is not particularly difficult, it’s considered more advanced because it’s a much more hands-on and lengthy process than simply updating to OS X 10.10 through the App Store.