Problems with audio after installing radeon hd 2400

okay, soo i installed radeon hd 2400 to my computer. downloaded the graphic drivers for it, worked perfectly fine. but then, i realized as i was playing music that i couldn't hear anything. so i searched and found drivers for the audio. but after restarting and installing drivers, the sound icon on my computer said that there was no audio output device installed. that happened quite a bit. i made sure that all the speaker wires we're plugged in to the computer, and nothing was loose. do you guys know what to do or how to fix my problem please? i need all the help i can get. I'm currently running on windows vista 32-bit.