Question about GRUB recovery using Debian 7.x LiveCD

[Bret Busby <bret.busby@gmail.com>]

Hello.

After a catastrophic attempt to install PC-BSD 10.1.1 on a GPT/UEFI
computer that had Ubuntu 14.04 LTS and Debian Linux 7.x installed,
with the installed bootloader being GRUB, with the result being that,
after the misleadingly stated successful installation, upon booting,
when it gets to the GRUB bootloader stage, it displays

"
GRUB Loading

Welcome to GRUB
"

and then, without any GRUB menu offering the options of which
operating system to load, it goes straight to the PC-BSD bootloader,
thence to the completely botched installation of PC-BSD, the
installation of BSD, being unusable.

Now, the request is this; please advise the stepwise procedure for
using a Debian 7.x LiveCD, to (attempt to) restore GRUB, so that the
GRUB menu is available and accessible and usable, and, detects the
installed operating systems, and offers them as boot options.

If a HowTo web page, already exists, for this procedure, please post
the link for it.

Whilst, prior to the catastrophic PC-BSD installation attempt, due to
the order of installation of the successfully installed operating
systems, the GRUB and the GRUB menu, were the Ubuntu ones, as Debian
7.x was installed first, then Ubuntu 14.04LTS, but I (and, it may be
incorrectly) assume that that should not create a problem, with
installing (if installation is required) and using, Debian 7.x GRUB
and its GRUB menu.

Thank you in anticipation.

-- 
Bret Busby
Armadale
West Australia
..............

"So once you do know what the question actually is,
 you'll know what the answer means."
- Deep Thought,
 Chapter 28 of Book 1 of
 "The Hitchhiker's Guide to the Galaxy:
 A Trilogy In Four Parts",
 written by Douglas Adams,
 published by Pan Books, 1992

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