All you are being asked to do the first time it boots is how to set up logical (software) drives on a single physical drive. For most people it probably won’t matter too much. For purists in terms of drive performance, settting up one logical C drive without a D drive makes the most sense. That way the drive heads aren’t forced to search back and forth between two physical areas, and some older application software might get confused or run less efficiently by having program and data files stored on two different logical drives. If there were two physical drives in the Sammy instead of one, it would improve performance to put the page (swap) files for Windows and Adobe applications on the second physcial drive. Some new netbooks are coming out with combo SSDs and HDDs for that reason.