Reformat hard drive. No sound. No longer have my system cd. I followed the other thread in here (howard_hopkinso) for the download on the intel page. This didn't fix my problem. Yellow icon next to Sigma-Tel C audio. I assume the download is not for my computer. Control panel > sound and audio devices. The contents of the volume and audio tab are grayed out. All Programs > Accessories > Entertainment > Volume properties returns an error message. "There are no active mixer devices available. Click add hardware to install one". Called HP, they charge $67 for replacement CD. Anybody got a clue as to what is going on or how to install a mixer device?. 542x Pavillion, XP.