That will depend on where they were located. When installing XP it automatically deletes the Windows. Program Files, and of course MyDocuments folders seen with 98. If you installed XP directly onto the existing Fat32 partition and had additional folders outside of the three mentioned you simply would browse for them.
If you removed the existing Fat partition in favor of a new NTFS type the only possible method is with a data recovery tool to undelete previous files. A large number of freewares can be looked over at http://www.myfreewares.com/category-1201-data-recovery-free-download.html to see if one there will help. The other method besides freeware or buying a full retail version of a software is a professional data recovery service. There's no guaranty on full recovery.
