You're trying to play a sound or video file on the computer, but there's no sound--there is either silence or an annoying ding. If you are the type that enjoys messing around on your computer and fiddling with various system files or programs, just to see what can be upgraded, modified, improved or deleted to save space, you may find yourself doing more harm than good. You can easily delete something crucial, like a sound driver, by accident. The good news is that it is very easy to remedy such a mistake.
Test the sound. Sometimes you may find that no sound is coming out of your computer when it should and you immediately think perhaps you deleted your sound driver. However, it may very well be that you did something far more simple, such as mute your speakers by accident. Perhaps, the sound does not work only when you use a specific program, suggesting that the program is corrupted and your sound driver is intact. To ensure the sound driver works, try playing a sound or video file using a different program. If no sound is produced, the problem is likely with the driver.
Check to see if the sound driver is still installed. Go to "Settings," "Control Panel," "System" and "Device Manager. Click to expand "Sound, video and game controllers." Your sound driver should be displayed. If you deleted it accidentally, it will say something like "No sound driver installed."
Check the status of your sound driver if it is still installed. Right-click on the name of your sound driver and click "Properties." It should say "The device is working properly." If it does not, or if it says it is working properly and it really does not, you will have to uninstall your existing driver and install a new one (see Step 2) or complete a System Restore.
Complete a System Restore to restore your computer to a date before you suspect your sound driver was deleted. The best way to do this is open your general help directory (on a PC, go to your desktop and press F1) and search for "System Restore." Follow the steps when prompted and you will be shown a calendar with highlighted dates. These are dates during which a snapshot of your computer's settings was saved. Pick the date closest to the current one to ensure the least number of potentially vital files lost. If the sound still does not work, repeat the process, going back to the second closest date and continue until you have sound or you have run out of dates. If this happens, you will need to install a new sound driver.
Uninstall the existing sound driver if you still have it installed. You will be able to do this by going to "Settings," "Control Panel," "System" and "Device Manager." Click to expand "Sound, video and game controllers." Now right-click and select "Uninstall."
Download and install new sound driver. Choose one from the "Driver Files" website or search for one according to your operating system in a search engine. Follow the installation instructions.