Downloading updates

Recently I have been having problems trying to update windows XP. At first it would download then it would try to install but fail. Then a message would come up saying that what i was trying to install did not pass the logos screen. Yes I do have a legit copy. Now when I try and do it, it tells me I need to update windows upddate so I accept and click update then it keeps repeating this step over and over. Any advice?