Need additional information... like what program are you using to burn disks?
What program were you using prior to installing XP and what os did you previously have? Even tho Windows Xp has burning support builit-in, it's not the sharpest knife in the drawer. It's best to use good quality recording software like Easy Cd Creator 5.x or Nero's latest.
Recording software designed for older Windows os's will not usually work in Windows XP.
