Because for each backup, you have to put on the cables, then take them off when you're done (rebooting in between, of course), and you don't want to have to open the case to do that.I think Harry is basically right, but why not open the case and leave the hard drive inside? (I didn't have a convenient mount, so I held the hard drive down with bent coat hanger wire and paper clips.)Harry Binswanger hb@xxxxxxxx