Realtek HD Audio Device intalled. Still not working?  

This is for a friend of mine. The computer says that there is not sound driver and has this button because there's no sound. I don't know much of his computer but whenever we try to download and install the realtek high definition audio driver, it installs succesfully, asks us to restart and when it loads it STILL says that there are no drivers for sound. He said he installed a genuine windows a few minutes ago and asked me to come to his house and fix it. He hasn't installed any windows updates yet. All I know is that he has an AMD Seprom 2500+ 1.7GHz 512MB ram and that's it. Anybody know WHICH version of Realtek should we install?

First thing is are you sure the motherboard has Realtek for the audio? Also the HD or AC'97 driver, as with it having an old Sempron in it is possible that it uses the older AC'97 driver.

Need to double check the model number of the motherboard to see what it has.