You can't click on the BIOS either. It's software dude, it's something that's run. It's loaded up at the beginning of booting up. You need to hit like DEL or F12 to enter into the BIOS and in there you can change settings to OC your CPU, RAM, and things of that nature.
You can't overclock a HD, there's no such thing. Their motors spin at a specific speed, and due to the hardware of the HD and the ribbons that transfer data it can only go as fast as it's rated.