You've kept secrets too! Don't pretend you haven't!
Anyway, its been so long since I installed this stuff that I can't remember where I got it or what I did. I know I've updated my drivers since then though, so whatever it is, its compatible with the latest X-Fi updates.
I'd check torrent sites for a Vista X-Fi driver CD image. I remember finding something that way, and that's probably what I'm using.