Boot to the XP CD and it will ask you which item you want to install XP on. Then, if you have a partition on there now, you need to follow the direstions on how to delete it. If I remember you press d to delete and then another key to confirm. The, create a partition by pressing C and then L to confirm. I can kind of picture it in my head but I'm sure I'm not exact. It's pretty self explanatory since you have done it with other OSs. It's all done from the CD.