If you don't have an operating system you don't need any drivers because your computer will be a pretty box you can put in the middle of the room and look at. Do you buy gas if you don't own a car?
Or are you just saying you don't have Windows XP but something else?
If you find out what the brand and model of the motherboard is, it's easy to find drivers for it, if they exist. Not all motherboards have drivers for all operating systems.