i was called to a friends home this afternoon to sort his computer out  which kept re - booting halfway through booting up. my friend had installed windows xp sp3 this morning and thats when the problems started ,after thinking things over and deciding the best options  for him ( as he's not very technically minded ) i decided to do a system restore for him and  things are back to normal. his computer is a hp and a AMD based system anyone any clues how to fix this bug . B)