I'm interested in purchasing the Pioneer DVR-AO4 burner. My question is this: Does it need to be installed inside my CPU or will it work alone? From its pictures it seems to be the kind of component that goes inside, but I have no vacant bays for its installation. I realize that some of you must be shaking your heads in disbelief that such a dumb question is being asked, but I honestly don't know. Thanks for your patience.