Hello - I have an external HD and the power to the casing fizzled out. The HD is still in working order so I simply installed it into my HTPC case. I liked the idea of external drives simply because they are not running at all times, which in my mind, makes me believe it helps make them last longer. Now that it is installed into the PC does it constantly run or only when I actually access it? Do external drives in cases last any longer than ones installed on a PC when only used for data storage and not running programs or operating systems? Thanks.