First of all, you can check your computer sound settings, to make sure the audio is not muted and is turned up.
If the setting is OK, try to reboot your computer. Rebooting computer can solve many computer problems. See if it helps.
There are many programs are running at the same time, you should quit all programs are running in your computer. Most sound cards can only play one sound at a time; therefore, if you play games or other multimedia programs, the sounds will be interrupted while videos are played!Make sure cable properly attached – Keep your speaker's or headphone cable attached properly, a broken connection can bring about "no sound" issue. Now, check your cable to see if it is connected properly.
After doing that, if the problem still exists, that means your computer need to reinstall a sound driver. Please don't worry, this problem can be resolved. What is a sound driver? Sound driver is a computer program which controls the sound card that attached to a computer, it operates sound in the computer. So, the question is how to install sound driver? You can try to update sound driver by device manager. Device Manager is a control panel applet in computer operating systems. Users can view and control the hardware attached to the computer. It can supply device drivers for your computer. So, this control pannel applet is very useful.
You may try these steps:
Step one Open Start menu, type Device Manager, and select it from the list of results.
Step two You will see sound, video, and game controllers. Select your sound card, open it, choose the Driver tab, and click Update Driver.
Step four Click "Search automatically for updated driver software".
Then the driver will be updated.
If this method can't help you, try this please:Uninstall the audio driver: open Device Manager, right-click the audio driver, and click Uninstall. Then restart your computer and Windows will reinstall the driver.
If Windows didn't find a new driver automatically, you can look for the driver on the device manufacturer's website and follow their instructions to download it. In fact, you can find all drivers for your computer from the manufacturer's website. But you should know your computer model number and your operating system at first, such as HP Pavilion 763k Desktop, Windows 7,32 bit. Then you can find drivers. You need to spend some time to do this, maybe a little boring, searching sound driver is a process and need patience. Maybe you can get assitance from your friend.
You can also update sound driver with DriverTuner. This software is very convenient, you needn't spend so many time to download sound drivers. Absolutely, it is easy to use. If you aren't good at computer skills, you will find it is an easy game. It has a huge driver database, all kinds of Windows computer drivers are available. It is compatible for all Windows versions,such as Windows 7, Windows 8, Windows 10, Windows VISTA, Windows XP, etc. Many users choose to install this software in their computers to keep the latest drivers are updated. Some guys don't like complicated methods, so DriverTuner is just suitable for them. Sometimes, we need some changes, new technology or software will make us more advanced. If you don't try, how do you know whether it will be changed? You can try it from here: http://www.DriverTuner.com/download/DriverTuner_Setup.exe