Sound doesn't work at all (HELP)

[Rileyg]

A few weeks ago my speakers stopped working and I have no sound. The speakers are fine on other computers but they don't work on mine. Even though they are plugged in correctly the pc detects no audio devices. Nothing seems to be working. Help?

 

[MarcFOnline]

There are three things I'm curious about right off the bat...

1. Have you recently installed any new hardware or software that could have affected your audio drivers?

2. When you go into Device Manager, are there any items listed as "Unknown Device"?

3. Do you have an add-on sound card, or is the sound built into your motherboard?

One of those should shed some light on a possible solution. Let me know what you think.