Hotfixes are something you download to your computer to make updates to XP. If there is a bug, you'd get this and then run it and fix whatever bug is there before. My thought is that these were downloaded to your computer and as long as they were run, you wouldn't need them anymore. I will say I don't have XP, but that is how I understood what I read when I looked it up. Hopefully someone could give you a better answer but no one in this house knows for certain how they work.