Just reformatted my laptop and everything reinstalled fine. Now XP is downloading the updates to bring me up to date, but there is one that keeps coming up all the time. I choose custom install, and after a few seconds it says installed! But its not, and appears a few minutes later. This is going on for few days. I also selected the express install option but no good. The file is:
MSXML 4.0SP2 Security Update (KB927978) 5.4mb
This is really strange....