So in the case of going to the Xfi the new card couldn't even be recognized by the new drivers until i reinstalled the entire OS, forcing the card with the drivers alone cause blue screens.
In this latest case of upgrading from a PCI16 to the Audigy 1, the system looses audio output after a reboot, if you remove the hardware from device manager and let the drivers install again the card will be fine until you try to configure the speaker setup eventually freezing up and no audio output until you uninstall/reinstall again.
This is all the pattern I always see when attempting to upgrade from one creative card to another without a complete OS reinstall.
So I know the .ini tracks uninstall and paths for installed games, I would like to save all that part of the system as well as backing up the smart menus if I am forced to do a complete OS reinstall to get the card working correctly. I believe it has something to do with old legacy audio drivers (the actual SB legacy DOS emulation drivers these cards install)or one of the other device drivers which don't seem to be uninstalled when you uninstall the rest of the drivers. I looked for a driver remoover program but was unable to find anything for creative cards even though some said they did.
Honestly this is the history I've had my entire life with upgrading creative's sound cards, I've always had to resort to a complete reinstall of the OS, I'm honestly surprised you needed more information, I assumed everyone had these issues.
*I Should also have mentioned this is the experience on my XP machine, Its 98SE/XP dual boot but I tried it on XP first to see how much trouble it was going to be and no suprise it acts like all creative sound card upgrades (Except DOS cards) do for me.