Modern cases have screws for 2.5" drives on the back side of the mobo plate. SATA connectors are all the same, except you want to use SATA 3.0 at 6Gb/s, not any other. Normally most if not all of your connectors are like this. Also it's probably best to leave it dangling than to tape it due to temperature.
I can hardly see the motherboard, from either side due to how the PC was built...
I also can't start any program from my old harddrive????So incase, I need to reinstall Windows in the future, is there a way to put Registries on a flash disc, so I don't have to reinstall everything?