Hi friends, i am asking this question for me and like ordinerry users. My system sometimes goes restarting and after that i cannot enter in to windows xp with the message NTLDR missing.
Or some times i get a message system32 not found. These failures are happend suddently by restarting the system. Why this happens?

Boot off the XP CD and run a chkdsk C: to fix any filesystem problems. You can copy NTLDR to C:\ drive from the i386 folder from the XP CD.

I think that would be a great idea.