Sound system is not working instead of installing audio driver.

Dear sir,
I am using laptop of compaq C738TU presario model and now currently i am using windows 8 operating system.Previously i didnt installed any driver and my system and sound system are working properly but today i don't know what happen suddenly my laptop speaker is not working,so after that i installed audio driver for windows 8 in my compaq 700 series but after that my sound system is also not working and also the sound is not coming from my headphone or earphone.....so i think there will be any driver related problem for sound system.....sir what changes can i do in my laptop so that my sound system will be working properly....please rectify my problem as soon as possible.
Thank You,

Regard
Praveen Kumar