While I was play a video on youtube, the sound (Realtek High Definition Audio) suddenly stopped and I can never get it back.

The speakers are working. The sound isn’t muted. I uninstalled and reinstalled the driver. Just there is no sound. What else can I do or check?

Check the sound card properties and check to see that the right playback (midi or ac97 device) is checked.

control panel > sound and audio devices > go through each tab and check for responses for sound through speaker configuration, sound themes...etc.!

Hi there, thanks for the suggestion. I have been through them and everything seems normal. The sound card is chosen in each tab.

Then there is a good indication that your sound card went bad if you have replaced the drivers and all. One thing you might try is to down load a codec pack.

I use and recommend that you use the K-Lite codec pack. This will install complete video and audio codecs that will cover just about all formats. The full version has media player classic ...a free standing media player with no resource hogging at all that is capable of playing audio and video including DVD.

Free-Codecs.com : Download K-Lite Codec Pack 4.8.5 FULL, K-Lite Codec Pack 4.8.5 STANDARD, K-Lite Codec Pack 4.8.5 BASIC : K-Lite Codec Pack is a collection of codecs and related tools

I installed it but still nothing happen.

I would say that your sound card died on you.