Normally you install P2P on another o/s partition or machine , or run it from the boot disc.
Just point it at the problem partition -in 2 secs, it makes all the drivers currently in the o/s )( and the hal ) adjust to the new hardware.
The issue you may have is XP may not have the drivers neded for the new hardware.
You would need to d/l XP drivers for the new hardware ( check the mobo site for XP drivers).
Then you can use P2P Adjust to inject those .