So I exchanged my Macbook Pro today at an Apple story, because of a defect. I am not quite sure if I properly reseted the Macbook Pro. I did the Command + R and I erased the main Macintosh HD and the partition Macintosh HD, but I am not sure if I unmounted the drives and if the format option under erase was set to "Mac OS Extended (Journal)". Furthermore, because of time constraints I did not re-install Mac OS x. Is the "Mac OS Extended (Journal)" the default option, and if not, does it matter if "Mac OS Extended (Journal)" was not selected? And would not re-installing Mac OS x have any affect on erasing of the hard drives? And also if anyone knows, do the individual Apple store by themselves do a factory reset? If not, should I contact the Apple store that I went to exchange my Macbook Pro to check if indeed successfully erased the contents of my hard drive?