I am using Windows 7 64 bit. Irrespective of whether I use IE9, Firefox or Google Chrome, I do not hear the sound when viewing video clips such as on CNN.com, except for the advertisement. However, the sound on youtube is fine. Perhaps a coincidence, but I have also lost sound on skype. I am running the lates version of Adobe Flash Player and have updated my graphics drivers
. No sound problems on Windows 7 applications like Media Player.