Oh well, shucks. I found a Driver Manager in Linux Mint, but it only works if you have an internet connection to begin with.

That computer is so noisy with all its fans and what-not, that I'm beginning to think it's not worth putting more effort into it (even though I liked it at first because it's got pretty LEDs in the case & a clear side panel). There's one more computer I haven't looked at yet, maybe I'll have better luck with it.