How do i install Dell Dimension B110 to my Dell desktop computer?

I have a dell dimension b110 speaker system (2 little speakers) and when i plug them into my computer, the light on my dell speakers come on, but nothing comes up on my computer. When i go to sound speach and audio devices, It says "no audio devices." What do i do?How do i install Dell Dimension B110 to my Dell desktop computer?Are the speakers powered and if so, are they plugged in?