"HP's website doesn't have XP drivers"
You should have checked HP's support pages before installing XP on that model.
The bottom line is you can't run XP on it if HP don't have the drivers (well you can run XP on it but several motherboard components won't work properly, if at all).
If you must have XP on it you'll have to get searching for drivers that work, it could take you quite a while.