I have read many reviews that mention that the R13 is setup as Raid 0. I want to purchase R 13 (R7-371T-78UV) which the specs indicate 256GB drive. Does this mean that this model will come with a single 256GB drive installed and I have the option to add an additional drive in the future in the slot that would have been used to setup for Raid 0? To be more specific, can I add another drive without the Raid 0 setting such that I can get the benefit from additional hard drive space to the already 256GB available? I read a review that indicated that the OS would have to be installed again in order to override a Raid 0 setting. I didn't realize that a Raid 0 could be set unless 2 drives were present but then I'm a novice.