UniBeast is a tool that creates a bootable installer out of your downloaded version of OS X. In order to start fresh, you’ll need access to a functional computer running Mac OS X Snow Leopard 10.6.8 or later. This is a requirement, as you need access to the Mac App Store to download OS X and create the installation drive. To start from scratch, booting the 10.6 Snow Leopard Retail DVD directly, check out iBoot + MultiBeast.