That ntldr is a windows program for some reason your system is looking for it.
1. Install XP (let it do whatever it wants, even if it takes up the whole disk)
2. Install your partitioning tool.
3. Resize the NTFS partition
4. Let all other space as unformatted/unallocated.
5. Plunk in the RH cd
6. When you get to this screen:
http://www.redhat.com/docs/manuals/l...partsetup.html
choose auto part.
7. When you get to this screen:
http://www.redhat.com/docs/manuals/l...kpartauto.html
Choose use existing free space
8. When you get to this screen:
http://www.redhat.com/docs/manuals/l...ootloader.html
Click on the change bootloader and insure you are using grub
9. Also, at the bottom of that last page I posted you will see the option to allow grub to install to the MBR. Make sure it does infact install to the mbr.
10. Finish install
11. reboot and at the grub splash choose an OS
12. Have a beer you are dual booting!
Good Luck!