Computers always have audio output devices. Did you check on the control panel on sounds, speech and audio devices? Just the basic stuff.
First, you have to make sure that the correct audio drivers for your computer are installed. Go to your computer manufacturer's website and go to their driver/ software download page, type in your specific computer info (model, name, etc...) and search for drivers. Once your drivers are listed, search for your audio driver; download and install it. Then you probably have to restart your computer. Then after doing so, see if your audio is working now. Hope this helps you out.