How do i get sound on a laptop?

Hi my boyfriend has a laptop and had sound. But when his teacher dumped it and cleaned it out or whatever. Something happened. How do you get it back because it did work.

Try installing the latest drivers for the audio controller.

You can get them from the manufacturer's support site.

I have a laptop and on the bottom right corner of the screen there is a little volume symbol make sure the box mute is not checked off. And raise the little barif it isnt already.