if you can't see your windows partition as well as the external partition, then go here and download and install redhat ntfs support. you have to download the package that matches your kernel version.
http://linux-ntfs.sourceforge.net/info/redhat.html
you'll then need to edit your /etc/fstab file to include your windows partition and external hard drive partition.
open up a shell terminal and use these commands first:
1. mkdir /mnt/winxp
2. mkdir /mnt/windata
these will create your mount points for your windows hard drives.
now the tricky part since i don't know how you have your external hard drive setup, you'll need to find the device block label for your external hdd.
you can try this command for that:
3. fdisk -l
that's a little "L" after the hyphen.
now you'll have to edit /etc/fstab to create disk entries for mounting.
/dev/hda1 /mnt/winxp ntfs auto, ro 0 0
/dev/hdXY /mnt/windata ntfs auto, ro 0 0
the X in the device block identifier is a letter of some sort like 'a', 'b', 'c', etc... the Y maybe a number like '1', '2', '3'. that all depends on how your external hard drive is hooked up.
then use the mount command as root (su into root in a shell terminal)
4. mount /dev/hda1
5. mount /dev/hdXY