cece, your sister (:-) sure) may just have disabled it in Control Panel/Sound, this would just disable the driver in the Device Manager, but you should still see the disabled driver in Device Manager. It should have a red "X" on it in the Device Manager screen. Since it is disabled and not not removed, it will not show-up in a Hardware Scan.
Open the Device Manager and look in the category "Sound, Video and Game Controllers" and you should find the disabled driver (with a red "X") there. Right-click it and "enable". Also what Operating system do you have and what Satellite do you have? This will be important if my answer does not work for you. Hope this will work for you, good luck