Fedora 12 install fails

[dogpatch]

I have Vista on the first disk drive. I use the second drive for Fedora. The automated update destroyed my Fedora 10 installation while trying to update to Fedora 12 - possibly because of GRUB issues. Now I am trying to install Fedcora 12 from the x86_64 ISO.

The first problem appears to be that GRUB was installed to the second drive instead of the first. As a result, when I reboot I don't see the GRUB menu, I just boot directly into Vista. I have tried to change the boot device order. When I tell the BIOS to boot from the second drive I get the GRUB menu, but the boot fails because of unrecognized file system errors.

Can anyone tell me how to install GRUB so I can boot Fedora 12. I am assuming the install program installed Fedora 12 properly on the second drive.

John.

Edit: Some more info:

When I set the boot device to the second drive I get the Grub menu. It appears to be the menu I edit when I try a rescue and edit menu.lst. When I try to use the Vista option I get

Error 13: Invalid or unsupported executable format

When I try to use the Fedora option I get

Error 17: Cannot mount seclected partition

The entry for the Fedora option specifies

root(hd1, 0)

Does any of this provide any useful clues as to what is going wrong?

[lmgutie]

It isn't clear, but I would check the drive order as seen by GRUB having swapped the boot order in the BIOS.
It may be that GRUB thinks now that your Fedora disk is hd0 and not hd1; then if hd1 is now the Windows disk then that explains your error message.

In that case you might fix it by doing something like:

grub
root (hd0,0)
setup (hd0)