you can start a secure encrypted ftpserver in about 20 seconds. here is more.
http://www.knoppix.net/forum/viewtopic.php?t=9076
http://www.knoppix.net/forum/viewtopic.php?t=18341
if i am not totaly misinformed you could then use winscp and atach to the sftp server from your XP box.
EDIT
just to see what would hapen I had a female friend (rather friend to my beloved monica) try setingup sshd with the above pages as guide.
took her just above 13 min from putting the 4.0.2DVD in to working sftp server.
she has NO linux experience and not much Win either (she can use Word to some extent, and she knows how to send/recieve mail). she had to read the pages a few times and so but...
/EDIT