Most probably the you have not install the "Codec" necessary to play **Audio/Video formats from Youtube site.
You can get the codec @ http://www.free-codecs.com/ , depending on you Operating System. If you have a windows system and not sure which codec to install, just install the latest version K-Lite Mega Codec Pack or K-Lite Codec Pack. (Support Win XP, Vista, Win 7)
Hope it helps.
"Courtesy is free but it will carry you forward a long way in a lifetime!"
Answers & Comments
Most probably the you have not install the "Codec" necessary to play **Audio/Video formats from Youtube site.
You can get the codec @ http://www.free-codecs.com/ , depending on you Operating System. If you have a windows system and not sure which codec to install, just install the latest version K-Lite Mega Codec Pack or K-Lite Codec Pack. (Support Win XP, Vista, Win 7)
Hope it helps.
"Courtesy is free but it will carry you forward a long way in a lifetime!"