nvidia nforce3 soundcard realtek ac 97 audio errors

I have an nvidia nforce3 motherboard with onboard soundcard. It is identified by XP as Realtek AC97 Audio. There are about 5 drivers I could find for it, and none of them work.
1) The Vista Beta 2 drivers from the nvidia website: no device is shown when I click Have Disk and point Windows to the place where I have downloaded the drivers. I have booted Vista with "Disable Driver Signature Enforcement".
2) The Realtek AC'97 Audio drivers from Windows Update: are downloaded succesfully but fail with the following weird error message:
"Windows found the drivers for your hardware but an error occoured while installing. Realtek AC'97 Audio. The system cannot find the file specified."
3) The Realtek AC'97 Audio drivers from my XP installation fail with the same message.
4) The drivers from the motherboard's cd (for XP) appear to work. The setup program finishes succesfully but upon reboot no soundcard is present, and Multimedia Audio Controller is still an "Unknown Device".
5) The Realtek AC'97 Audio drivers from Realtek's website report: "The Microsoft Bus driver must be loaded before installing Realtek HD Audio driver !" (the space between r and ! is not inserted by me)
Any idea why this doesn't work? Has anyone with a similar configuration managed to get the damn sound working?

I've solved my own problem, after days of trial-and-error.
Investigating setupapi.dev.log, I've noticed that the file not found was "drmk.sys". I found it on reliz.ru from some other Windows service pack. Then I tried installing again and noticed "portcls.sys" was needed also. I downloaded both and put them in c:\windows\inf\ and then the installation worked.
Hope this info helps someone.
"Adrian VELICU" wrote:

I have an nvidia nforce3 motherboard with onboard soundcard. It is identified by XP as Realtek AC97 Audio. There are about 5 drivers I could find for it, and none of them work.
1) The Vista Beta 2 drivers from the nvidia website: no device is shown when I click Have Disk and point Windows to the place where I have downloaded the drivers. I have booted Vista with "Disable Driver Signature Enforcement".
2) The Realtek AC'97 Audio drivers from Windows Update: are downloaded succesfully but fail with the following weird error message:
"Windows found the drivers for your hardware but an error occoured while installing. Realtek AC'97 Audio. The system cannot find the file specified."
3) The Realtek AC'97 Audio drivers from my XP installation fail with the same message.
4) The drivers from the motherboard's cd (for XP) appear to work. The setup program finishes succesfully but upon reboot no soundcard is present, and Multimedia Audio Controller is still an "Unknown Device".
5) The Realtek AC'97 Audio drivers from Realtek's website report: "The Microsoft Bus driver must be loaded before installing Realtek HD Audio driver !" (the space between r and ! is not inserted by me)
Any idea why this doesn't work? Has anyone with a similar configuration managed to get the damn sound working?