Comment 27 for bug 1024383

> You don't run update-grub from a live session; you have to chroot into
> the install and run it from there

of course :)

> , where you are running the correct version, regardless of how you booted the livecd.

what do you mean by 'version', is it 'grub-pc' vs 'grub-efi' ?
if yes, which entries would you hide if both grub-pc and grub-efi are installed in the installed Ubuntu? (i would suggest no hiding in this case)

(In post #25, I thought that you were referring to [[ -d /sys/firmware/efi ]] when writing 'At update-grub time, you know if you are EFI'. But i think now that you were refering to grub-efi / grub-pc presence in the install , as that would make more sense. Sorry for the confusion.)

> is it possible to install windows on a gpt disk without EFI?

i don't know. Also, maybe OEM have more install possibilities than a standard Win user.

> you can't boot windows in a mode other than the one grub is booted in.

agreed. And the mode grub (of the installed Ubuntu) is booted in is the mode in which the firmware is set up to boot the HDD (which can be different from the mode to boot the USB/CD).