memory core dumps???

where do i start, i had installed everything with no probs, then powered off and on. kept sort of looping, anyway before it would power off again it would give a blue screen with some info on it, but couldnt read it in time
anyway i tried to reinstall xp again and start from scratch, but when it comes to the point where it says press enter to install xp etc and then i can partition drive etc it goes to format to ntfs say and then each time goes to blue screen of death, eithere error is bad pool error or irq not less than or equal something like that
have thought of memory core dumps but i dunno plz help