Yes, boot with the first CD or with the DVD into rescue mode by typing; linux rescue
Answer a few questions and read the on-screen messages, pay extra attention to the chroot screen. When ready follow the advice about using chroot then type something like;
/sbin/grub-install --recheck /dev/hda
When done press the three key combo of Ctrl+Alt+Del to reboot the system.
If you want the Windows bootloader to boot Linux then see;
http://www.redhat.com/advice/tips/dualboot.html
.
