Comment # 3 on bug 907672 from Walter Augenstein

Neil, you were right about the prefix variable - grub2 uses it for some
internal purposes, however, changing the name did not fix my Windows boot.
Yesterday, I spent most of my time looking through grub2, but the highlight
of the day was when I discovered how to boot the EFI Shell off of the
Toshiba Bios Reinstallation CD.  The EFI Shell is a collection of
utilities that interrogate the Bios and the EFI subsystem and can be
used to modify EFI parameters.  In particular, it can be used to display
and modify handles, diskpaths, and uuids.  I think that I am on to
something here and will be occupied in exploring this for the next
few days.  Nobody has to seriously worry about this problem for the
time being.  I will get back to you when I have more conclusive
information.

Thanks,
Walt