No sound coming from speakers?

Okay, so a friend of mine reinstalled windows...so now all of my programs are gone (obviously). Well i hate to say but, i am very much so computer ILLITERATE! Seriously. well, he told me I needed to reinstall everything again. I didn't pay him no attention. I tried troubleshooting the problem, But it says everything is working properly. It says no mixer device installed. I have tried EVERYTHING that the trouble shooting thing tells me to do, and still nothing. Oh, and it says to add hardware, where it says manufacturer, my speakers are not listed (if that's even what they mean). I don't know what I'm doing. Does anyone know what i am doing wrong or not doing at all? I appreciate all help. Thank you :)