When audio is not working on your computer it usually means there are some simple speaker and sound card-related issues that can be fixed to take care of this problem. It is not always necessary to swap out your sound card for a new one, as the origin of your problem could lie with your sound card drivers and your existing card may be able to be fixed via a couple of relatively painless methods.
Check for the latest sound card drivers for your computer. Has your hardware been adequately updated of late with these sound card drivers? If you have reason to believe not, click on "My Computer" and select "Properties".
Click on the "Hardware" tab and then on "Device Manager".
Right click on the driver(s) listed under "Sound, Video and Game Controllers".
Choose the update option (there should be a "Driver Update" button), and wait for the update to begin. (If the auto update option does not work, skip to Step 6 below.) The Auto Update Wizard should pop up. Follow the Auto Update Wizard. Updating the drivers for your sound card should be a cinch, as a Wizard for the sound card driver installation process should pop up that will take you step by step through the painless process. A few clicks of the "Next" button inside the Wizard will take care of most of the work for you.
Restart your computer for the driver change to take place. Failing to restart the computer will leave your sound problems the same as before.
Go online to find drivers manually if the Auto Update Wizard does not work for you, or if you simply choose to have more control over the upgrade. Visit your official computer manufacturer's website, where sound card drivers for your model can be found, downloaded and installed.
Input your computer model number into the website when prompted and search for associated drivers to complete the driver acquisition process. Your computer model number can be found either on the bottom of your computer unit, or via documentation and manuals that ship with your PC or Mac. After installing the downloaded drivers, restart your computer.
Try restarting your computer. Often this may take care of your apparent sound card problem. Sometimes the most obvious solutions are the ones that work, and these should be tried first. Properly shut down your computer through your desktop menu as opposed to holding down the power button--unless your computer is completely frozen.
Take your computer to a professional repair person or send it to the manufacturer for repair if none of the above steps worked. Your sound card may need to be replaced.