what are the hard drives used for? can u record tv, can u put avi or divx movie files on it? do they have capabilities of hooking up to a laptop? can you put files such as jpgs and mp3s and dvd movies on it and play thru tv and surround sound receiever? does it have usb and what uses does it have. what kind of wireless advantages are there. can it burn tv onto dvd disks.