i have the systeme sound but dnt have multimedia sound windows7

hi guys hows going? hope ur fine
so im new here and i have a problem that make me sick :s
i have an hp hdx18 1150-ef windows 7 64 bits the problem is that i can hear the systeme voice but thers no multimedia voice (mp3,mp4,media player.vlc....and even games) even youtube and dailymotion dnt have sound plz help me i really need it because im a journalist in a frensh music magazine and thnx

aaa anathor thing is that i remarqued that i have a new driver that i didn't installed its called "nvidia high high definition audio" (i even dnt have an HD tv x) lol whats wrong with my windows )

help plz

heeey hello plz ansewr me :s here is anathor error that is killing me :s : when the my windows 7 was fine i used to have a sound controller for each program i run but now i have nothing ! :s