Windows wont load

i have windows 2000 pro on my laptop but it orginaly had windows xp on it i cant get my laptop to load windows there is a missing start up file windows system32 or something i called HP for a restore disk and they sent me XP and it does not work on my Pc i called them back and they said that is does not matter if i have windows 2000 pro that the quick restore disk for windows xp would work am i not doing something right