Xp drivers for c771tu. i purchased c771tu laptop and i install xp sp2 but no driver in hp.com. plz

Question

i purchased c771tu laptop and i install xp sp2 but no driver in hp.com. plz give the web address or mail drivers whichever u think easy... i email id is [e-mail].. thank u..

ii have compaq presario c785tu pc sound and audio not working . control
panel shows no audio device . in device manager other device is marked
question mark . pls help