So first off, a big thanks to the people who have helped me thus far, I really do appreciate it!
And now: I've been poking around in my case like a macabre computer version of Dr. Frankenstein, and I've located what appear to be two hard drives (?) one on top of the other (or beside the other, when the tower's on its side). Each is a grey rectangular box with a large flat "cable" going into it, and a bunch of about 8 small colored wires.
So... how do I unhook this sucker? The flat "cables" seem pretty well anchored in, is that what I'm removing to do farther testing, or what?