Start a thread in the Installation forum, post your hardware specs, your grub.conf file, and the output of fdisk -l, and the grub error message, and maybe someone will spot something. The more eyes looking at the problem, the better chance for a solution.
Grub2 is available in the fedora repos. I haven't tried it, but maybe if you selected it during installation, it would work.
Can you boot a LiveCD? That would be a way to install grub2. Or, the Super Grub Disk:
Definitely 64 bit.