Good question.... me too
I've been on XP for a whoppin 48 hours now so I don't have a lot of answers :/
It seems like some stuff thinks it is NT and some stuff thinks its 2K when it comes to drivers.
The auto compatability check on the XP CD helped me know what to change....... but for
the most part, I just let it upgrade it's little heart out and then tried apps. If one didn't work, I
uninstalled it and re-installed. (that solved almost all isssues.. particularly with games)
Beyond that, I downloaded both (NT and 2K) drivers and gave them a try.... if it worked, I left it
If not, I tried the other.....
Side note: The old scanner I have (ScanJet 5s) that XP said will never work, is runnin like a champ... ? so don't be afraid to try!