My audio wont work on my computer?

ok my speakers work on my other computer and its nto the sockets i have 4 and its highly unlikely they all 4 broke at the same time and the speekers were working on the computer before again its not the speekers they work still and my computer is a 2007 hp windows vista please respond if u awnser i comment telling you about what you wrote like if i already tried it or somthing =) so please respond