NOT everyone who buys a Desktop at Best Buy is a novice that needs hand holding just the vast majority, I my self recently purchased a Desktop, the only reason I went to Best Buy is because I had a networking schematic due the next day and did not wish to sit in the library until close go home, turn around and get up a few hours early go to the library, go to work then hopefully head straight to class with a finished assignment if not head back to library! I couldn't wait for a new MoBo and PS to be shipped to me, it was just easier to drop 400$ on a decent box throw the HD that came in the box into my scrap heap toss my HD in and jump right back into Linux, with a total down time of maybe 3 hours between diagnosing and up and running. Needless to say this is not relevant to the car analogy one cant just yank an engine out of one chassis and drop it in the next but with some minor modifications you can yank a Hard drive, I may also add I was luck I had not built the Linux kernel I was running optimizing it for the old mother board