Ok, thanks for the info. This way I can check if there are specific issues with that hardware. Nothing specific found. Your MoBo has an ALC650 soundchip and that one seems to be a bit picky. But everybody seems to solve his problem with newer drivers.
On the Seanix site, the latest driver for this chip is from 2003 and that one may have troubles with SP2, as you mentioned in your first posting. Did you try the driver from the old mainboard CD first? This could have been the wrong step:

You mentioned duplicated entries in the device manager. This could be from trying the several driver packages, shouldn't be there and indicates that something with the (de-)installation has gone wrong. Uninstalling one driver will not remove remainders of the other. I would have done this list now:

0. Try a uninstall of the driver from control panel. (Mainly to remove it from there, this won't help a lot)

1. While in device manager go to the top of the window and select View ---> Show hidden to make sure that all devices are shown. Delete all devices provided by the audio chip.

2. If possible, clean up registry from all references to the driver files

3. Go to Windows\inf and delete all ALC*.inf and ALC*.cat files

4. Reboot and ignore/cancel all upcoming "new hardware detected" and "have disk" -windows.

5. Back on Windows, run the latest driver (3.91) installer again.

I assume you tried this (and repeated XP installation) 20 times already, but from the symptoms you described I don't believe in a hardware issue yet. Anyway, "driver installation gone bad, redo from scratch" is a thing I know well from my audio driver experience... Please tell us if you tried something like this already and what happened. As long you give lifesigns, we know your kids didn't trade you for a new computer and we try to help you... :mrgreen: