No sound when playing Youtube or online videos

Hello kontham,

·        Was the sound ever working fine before on the Internet?

Check if the Internet Explorer settings are set to play sounds:

1.     Open Internet Explorer settings by clicking on Tools, Internet Options.

2.     Click on the Advanced tab, look for the setting that says ‘Play sound in webpages’ Under Multimedia.

3.     Place a check mark next to it.

Run Audio troubleshooter:

This will Diagnose and repair problems with sound and audio automatically.

1. Open the Playing Audio troubleshooter by clicking the Start button, and then clicking Control Panel. In the search box, type troubleshooter, and then click Troubleshooting.

2. Under Hardware and Sound, click Troubleshoot audio playback. If you're prompted for an administrator password or confirmation, type the password or provide confirmation.

Check out this link for more information:

http://windows.microsoft.com/en-US/windows7/Tips-for-fixing-common-sound-problems

Reinstall Audio drivers:

To uninstall a device with Device Manager:

1. Launch Device Manager.
2. In Device Manager's left panel, open the node that represents the type of device that you want to uninstall and then right-click the device entry.
3. On the shortcut menu, click Uninstall.
4. On the Confirm Device Removal dialog box, click OK to start the uninstall process.
5. When the uninstall process is complete, unplug the device.

Note: Make sure that you download the latest drivers for your Audio card from the Manufacturers’ website before uninstalling the drivers. Alternatively you can install the drivers from the CD that came along with the computer.

Thanks,
Irfan H, Microsoft Answers Support Engineer. Visit ourMicrosoft Answers Feedback Forum and let us know what you think.