... you'll want to play around, organize your files, and learn the lay of the land. A. 3.1. Phase 1: The Installer Here's how you install Leopard onto a drive that doesn't have a version ... to upgrade the copy of Mac OS X that's already on your new Mac. That doesn't mean, though, that you can't perform a clean install at all. If you use the Erase and Install option, ... Upgrade installation or an "Archive and Install" (that is, a clean install). You may have received a different DVD, however, thanks to Apple's Software Up-to-Date program. (That's...