Grandma’s machine is working now. I went out to Discount PC Outlet and got, literally, a $10 used (Creative Soundblaster Live!) sound card. I popped in the new card, disabled the onboard one in BIOS, and the card worked flawlessly on boot. I literally didn’t have to do a thing. I have the thing hardened thanks to Firestarter. Nmap just looks at it and shrugs. Compare this to a firewalled (the built in one :\ ) Windows machine where Nmap finds two open ports lists at 100% certainty that the machine is running XP SP2, which is correct.
I also learned something accidentally today, which is sometimes the very best way to learn. I had forgotten to plug the speakers back into the alarm, yet it got me up anyway. I was confused, and told the alarm to play music again only to discover it had an internal speaker! o_O You learn something every day, I guess.