Your Dell PC probably won't have one. They are distinguished from normal ones by a different colour USB port though, usually red or blue. Blue is used for USB3.0 nowadays though, so I'm willing to bet it'd be a red USB port.
Also, follow the advice Novuake gave and buy a powered USB hub. It'll deliver a more uniform and constant power source than your motherboard, and it can be placed at convenient spots easily (where power USB ports are generally on the rear of the motherboard). And they are cheap.