I have an HP Pavilion dm1z-4000 CTO Entertainment Notebook PC, model LY133AV. I have had the laptop for 1 1/2 years and up until today, there have been no issues with sound. Today, when trying to view a video, there was no sound coming from the internal speakers, however when I plugged in headphones there was sound. For awhile. After watching 45 minute show on DishOnline, when I tried to watch the next show, I had no sound at all. Not from internal speakers, nor from headphones. I checked several forums and tried several suggestions including disabling all enhancements, checking for accidental mute settings, etc. I tried configuring the audio and got the message "test tone failed to play". The only sound I get is when the computer is rebooted, I get the start up tone. I have checked my Window's updates and do not have the update #KB2962407. I do not install all updates, as I have had troubles with my computer before after installing Windows updates automatically. The last Windows Update that was installed was #KB2952664. Any suggestions. I really would rather not do a restore to previous date for a couple of reasons. I have not installed any updates recently. The only thing I have done is today I set up the laptop to get the internet via WiFi instead of the Verizon broadband I had been using. So when would I set the restore date for? There was sound from internal speakers yesterday, headphones only for about an hour today, then no sound. Any help would be greatly appreciated. I have Windows 7.