I ill-advisedly deleted the Raspbian files that were not directly needed by RetroPie, thereby removing the option of using the machine as a desktop replacement. The Pi 2 is currently running an installation of RetroPie 2. The Model 1 Pi has been doing duty for a couple of years as a media center, and is dedicated to running XBMC. I have a couple of older Raspberry Pi machines, each of which is limited to a single task. Installation Guide for a three-in-1 Multipurpose Raspberry Pi: Installing a Media, Gaming, PC Replacement