icer, even if the new xp install is on a fat32 partition, it will still access any other ntfs partitions. it is purely a matter of file permissions, in this case.
wineglass, did you choose to use encryption to make your files more secure? if not, then log in as an administrator (your standard account probably has admin rights, unless you wanted any form of security) right click on the folders or files in question, and somewhere in the properties should be an option to take ownership of these files or folders. you will need to switch off simple file sharing, if it is on. you can search windows help, or these forums for more detailed instructions.