I just put together my pc about a week ago and cant figure out what is wrong with the sound.

DFI Lanparty pro 875b mobo
2.8E pentium 4
512 ram
c-media ac 97 audio(onboard)

Anyways before I got my new processor I had the mobo in another case and the sound was working fine, but I was using front x....a frontside audio that comes with the mobo and plugs into the mobo seperately from the rear audio ports. Anyways well after I changed cases I didnt put the front x in this case and once all was installed and everything I have no sound. After I thought about it I have never even tried to use the rear audio ports b/c I have only been using headphones in the front ports. Anyways if I could just get this last little problem fixed I can finally say my computer is working perfectly. Well, I have uninstalled/reinstalled the audio driver numerous times and I wish I could see if the front audio still worked but I dont have that case here with me to try it out as of now. Anyway, I was thinking that this is probably either a defective mobo (please NOOOO) or maybe some settings on it. Also I have checked all volume controls and they seem to be set fine and mobo is set for ac97 audio. Let me know what you come up with.