Lost sound after formatting

Hello,

I formatted my computer its a gateway and im using windows XP, and i dont have any sound at all. whenever i plug in my headphones it doesnt recognize that there is a device there, and i have Audio Codecs and Legacy Audio Drivers installed in my device manager. when i check my sound and audio devices it says that there isn't one, im pretty sure i was using realtek. I used a scanner to see what drivers i was missing and it didnt show anything for sound. Oh and im using my motherboards sound card and i do have the operating system disk, please help