Hard drive and install of 10.8 issues

I wanted to wipe my computer, so i held the option key on boot up, and I managed to wipe it. But it locked to 16 gigabytes when it's 10 times more than that. I need to unlock it, and make a boot start usb drive I belive to make this work. But I don't know how to do this. I'm unable to go out and but help/get it or buy new parts or things like that. So i need to figure this out soon. Thanks for the help if you can.