UPDATE 2: Googling the error code actually may have helped. I found this post on the Wisetechie Blog where the author had exactly the same problem. He was trying to install the same drivers I am, and it kept aborting, and he got the same error message. It turned out that the driver install checked for later versions. When it sees XP Service Pack 3, it thinks there's a newer version of itself already installed and aborts without giving the user the choice of continuing to install the patch. The problem is that SP3 does not contain an updated patch, so you're stuck. I'm going to try his solution as soon as I can figure out how to do it--he changed some registry value so that the installation program wouldn't see SP3. I was thinking of doing a System Restore back to before SP3 was released, then going and getting SP3 again once the audio driver installation is done.
UPDATE: OK, so I checked the BIOS/CMOS settings, and I have the onboard audio enabled. I unplugged the front panel leads just in case (found a forum post where that helped someone for some reason.) I then went to the FoxConn website and downloaded their updated audio driver--it's old enough that I think it's probably the same as the one on disk, but it was worth a shot. Same as the one on the disk, it goes through most of the installation and then gives me this error message. I have no idea what this means. I'm going to go Google "installation error message 0xE000027" (I'm assuming that a "0" is a zero.)
The bad news is that I missed the Gun Nuts Radio Show tonight . . . again . . . because I still have no sound. I don't understand it. I just checked the System tab on the control panel, and under "Sounds and Audio Devices" it just says "No Audio Device." What gives? The thing's got to have some kind of audio installed. It's killing me.
I've got something I'm going to try, and then I'm fresh out of ideas. Anybody else got any?