Youve just received a brand new Raspberry Pi 3 ? the latest, most powerful version of the popular mini-computer that has taken the maker world by storm. If this is your first Pi, then youll need to get a copy of the Raspbian OS installed. But if this is just the latest in a long line of Pis, you might prefer to upgrade your existing install, which is almost as simple as transferring the microSD card from your older Pi into the new model and booting. Almost as simple, but not quite.