Logitech X-540 Computer Speakers "youtub dont play sound" Questions

...sound for the required audio might be muted My volume works fine on aim & windows media player but it dont work on youtube or other music websites. I checked my control panels but it says ...

...im on games some sounds bug out or just dont play when ii know there should be a sound there, please help!! my sound card is realtek ac97 and 5.1 is enabled. did you turn off onboard audio in the ...

...dont have the right audio cables? how will i know if my speakers isnt working anymore? am i supposed to install something in my laptop for the speakers to work? its a secondhand Hello, have you got ...