I will say right at the start that this is an XP x64 issue, but it seems to be that the same machine has the same problem with XP x86.
So, my issue is that I can turn on the computer but have no sound. In order to enable sound, I must go into Device Manager and uninstall one of the Microsoft UAA Bus Driver for High Definition Audio. After that, I can scan for devices, and it will reload the bus driver and then the Realtek driver as if it had been there all along. Sound works correctly, the issue is simply it will not load at startup.
I should also mention that if I scan for devices before removing the device initially, the Realtek device is not detected.
So, my issue is that I can turn on the computer but have no sound. In order to enable sound, I must go into Device Manager and uninstall one of the Microsoft UAA Bus Driver for High Definition Audio. After that, I can scan for devices, and it will reload the bus driver and then the Realtek driver as if it had been there all along. Sound works correctly, the issue is simply it will not load at startup.
I should also mention that if I scan for devices before removing the device initially, the Realtek device is not detected.