Onbaord sound question

Hi, I'm trying to help a friend out with a sound problem on his computer. He has a HP 7955 with onboard sound(AC97). It is running Windows Me with afresh install. The thing looses the driver for the sound after every startup. It has the latest driver installed also. After the reboot, you have to update the driver and install one of the older ones to get the sound back, if you reboot with it, the sound is gone again and the you can update back to the newer driver. The pc came with Windows XP originally but he had tons of trouble with it and formatted and put Me on it. Sound like time for a sound card to replace the onboard sound rois there something he should try first? Thanks,

Scott