As always, backup before any big changes and even those PCs that came with XP preinstalled had ways to make restore CDs. As to those pirate XP installs, you deserve all the trouble and no support.
-> Read http://www.aumha.org/win5/a/ntfscvt.php
We have a "new to us" PC with XP installed on a hard drive that is formatted as FAT32. We have no recovery disk for this OS. Can we change it to NTFS without reformatting? (Here comes the, no. ) Well then, can I move/copy it to another drive that is formatted NTFS? (Another, no.) Geeeez....that was no help.
So what are the risks of leaving it like it is?
Link provided to...other.