Windows update. i downloaded this update which vista labeled as important (dumbasses) now my sound

Question

i downloaded this update which vista labeled as important (dumbasses) now my sound is gone, i'm running vista home basic as my OS and using a HP 530 notebook processor intel celeron M CPU 440 @ 1.86GHz Ram 1015mb system type 32 bit operating system.the update i downloaded is called Conexant - Audio - Conexant High Definition Smartaudio HD2