Making Externally connected devices HD and OD bootable

Do you have a question? Post it now! No Registration Necessary.  Now with pictures!

Threaded View

Is it possible to make these devices connected by USB Bootable?
What I mean is its normal that if you boot from a CD you have to use
the internal optical drive; the same also with the O/S, it must be
booted from the internally installed harddrive.
Is there a turn around for this?


Re: Making Externally connected devices HD and OD bootable

Quoted text here. Click to load it

Depends on the bios in the system.  My bios will only show usb
drives if the drive is present, with a bootable mbr, when the
system is powered on.  In that case, the bios setup program will
show the usb drive in the list of drives where you select the
boot order.

Regards, Dave Hodgins

Change to to reply by email.
( has been set up specifically for
use in usenet. Feel free to use it yourself.)

Re: Making Externally connected devices HD and OD bootable

Roy wrote:
Quoted text here. Click to load it

I boot from an external 5.25" USB enclosure with a DVD drive
in it. I boot from my collection of Knoppix Linux LiveCDs, via
that external drive, or by using the internal drive inside my
computer. Either will work.

I have also booted from a USB flash, where a 1440KB image of a
DOS floppy was copied to the flash drive with "dd". So somehow, my
BIOS was able to boot from that (I never expected it to work).

The USB module in the BIOS, may have basic booting abilities,
as well as certain emulation modes, to convert a device into
something usable. But chances are, there is no documentation
about this.

There was a short interval of time (maybe a year), where
the BIOS had a separate page with details about what USB devices
were connected, their emulation mode if any and so on. The BIOS
writers have since made that invisible, and on newer computers
or motherboards, it no longer gets its own screen.

Note that, if you take your WinXP hard drive from inside the computer,
and place it into an external USB enclosure, it will not boot properly.
There is a problem with unmodified WinXP, in that the USB chain
gets disconnected during the boot sequence, and that prevents
the boot from completing (I think that is what gets broken).
Some clever people have figured out how to fix it, but the recipe
is not particularly easy. Some other OSes are more friendly with
respect to booting and operating from USB.

So one of the elements to being bootable, is whether the OS
can maintain the connection over USB, while booting is completing.

The hardest part about USB booting, is figuring out how to
make a bootable device. For example, it took me a while to
get something to work with my USB flash sticks, and my
first few attempts were not successful. Even a Knoppix option,
to make a bootable Knoppix environment on a flash stick,
didn't work (it would not boot for me). So there are a
number of recipes for making bootable devices, which may
or may not work. There are too many variables,
to predict with any certainty what will work.

I could not find this document on , so had to find it on another site.
This shows what options used to exist. See section
on PDF page 8.

OK. Found it on as well.


Re: Making Externally connected devices HD and OD bootable

Quoted text here. Click to load it

Thanks for that interesting info paul!

Re: Making Externally connected devices HD and OD bootable

Roy wrote:
Quoted text here. Click to load it

It's a rather difficult hack to get XP to boot from a USB drive

You may want to go with Linux...

here is one example /

Re: Making Externally connected devices HD and OD bootable

Quoted text here. Click to load it

Thanks for that info but its really possible to do so but not 100%
applicable on  all Windows run PC?
How about if you boot with XP Cd from an external Optical drive
supposing your internal OD does not work anymore?

Re: Making Externally connected devices HD and OD bootable

Roy wrote:
Quoted text here. Click to load it

What I always keep handy is a bootable "live" Linux cd that can access a
failed or troubled Windows installation.

Just for example  PCLinuxOS live cd can easily read and write to an NTFS
partition...and back data up to an external drive

Re: Making Externally connected devices HD and OD bootable

On Sat, 1 Aug 2009 19:40:09 -0700 (PDT), Roy

Quoted text here. Click to load it

As David and Paul have pointed out, regardless of whether
the PC has windows installed on an internal hard drive,
regardless of whether the internal optical drive works or
even if there is no internal optical drive, in order to boot
an external drive (connected by USB, or perhaps firewire but
I've never booted a firewire connected drive that I can
recall), the system bios must support booting from the bus
the drive is connected to, not just in theory but that it
actually successfully enumerates the connected bootable
media as a valid boot volume, and that volume is selected as
the one the system should boot from.

Whether this is a flash drive, optical drive, hard drive,
etc, any are possible if the system bios supports doing so.
On most modern systems this is possible but going back 4 or
more years it is less and less common to be a feature that
works properly, or further back isn't supported at all.

The key in booting an external drive is what the goal in
doing so is.  That goal will determine what operating system
you'd boot to whether it be a windows installation disc, a
windows PE, Linux LiveCD or equivalent, DOS, a specialized
(often a form of DOS) OS put together for a software
application to run like a memory test, backup or
partitioning software, etc.

Personally I find booting to a USB thumbdrive to be the best
option unless you'd regularly have another type of external
drive connected, as they are quite inexpensive in lesser
capacities, ultraportable due to their small size, more
rugged and less prone to unexpected failure like an optical
disc being scratched, an optical drive becoming too dusty or
it and hard drives having mechanical failures.

Whatever your goal there is probably a custom made image
that supports it so you would not have to build it by hand.
Legal licensing issues aside this also goes for Windows
Portable Environment images, they can often be found on
filesharing websites.

Re: Making Externally connected devices HD and OD bootable

Quoted text here. Click to load it

Well - this is where I stand:

1) I now have my Fantom 1TB external hard drive connected to the
computer via eSATA => SATA, not USB.
2) I figured it would be faster than USB, and it is.
3) I have two partitions on the Fantom - 1 = 100GB; 2 = 900GB.
4) I have two machines LAN'ed together via router.
5) I have some test folders and files in the second partition, and
they read and write fine on both machines where whichever machine is
not selected in my KVM, it works through XP's sharing.  I expected
6) The machine to which the Fantom is connected has one internal hard
drive.  The BIOS on that machine shows both the internal drive and the
Fantom.  Using F8, I can boot from either one, and I tried both when I
tried to install XP from CD into the Fantom's first partition.
7) The installation progresses through the initial  file loadings,
then at the first re-boot to continue the install, Windows comes up
showing 39 minutes to go.  This is normal with XP installation.
8) Then it fails with this error in the drive:\setuperr.log:




So, unless someone can suggest something, I think I am not going to be
able to make the Fantom bootable, dang it.

Thanks for any ideas and/or sympathy,


Site Timeline