Once fixed and rebooted into fedora add this to /boot/grub/grub.conf to enable you to boot into windows
title Windows Xp
rootnoverify (hd0, 0)
and remove the line 'hiddenmenu' else you won't see the menu unless you hit a key.
(may need to use (hd1, 0) , (hd0, 2) etc, depending which disk/partition windows was installed on)