OK so read pendrivelinux and various others.
Can make my 640GB portable HDD USB bootable, with multiple OS etc.
I know the casper limitations - ie 1!
Currently using Ubuntu, but also came across CoLinux/Pubuntu.

What I want to do is this:

Create a Ubunutu (or other simple to use) installation that can:
a) Be booted in it's own right from portable USB HDD (can't be only OS so already setup to multiboot and doing it from a Live ISO).
b) Can be booted from WITHIN Windows as a window (QEMU?)
c) Can be loaded from WITHIN Windows as a bar (Pubuntu style)

At the moment I'm part way there- and it seems to *almost* be a case of Casper is the workaround...
Any advice/step by step solution?

I can't be the only one wanting this portable flexibility...

booting from usb works on newer computers.(otherwise use puppy superfloppy mode)

b:with virtualbox, linux OS can be single file


try installing the most simple solution first if you are new to linux

Well Also; Welcome to LQ!
I can help you 2 of those questions...
a) is pretty easy; but how do you wanna do it?
if booting from iso-on-usb with grub2 you can have multiple *buntu's on there
see here
http://www.linuxquestions.org/questi...how-to-775347/

and )b is also doable
with PQemu Portable-Qemu
http://www.linuxquestions.org/questi...ml#post3969567

it runs from a folder, usb, cd, etc
and you can make virtual qemu-img's and connect them like drives using Grub
so, I can expand on it if you wish?

Thank you for responses.

I think it almost makes sense.

a) I have done A (using Grub4dos) on my portable HDD and can boot the Ubuntu in to the LIVE CD part. However I am missing various drivers.
Ideally I'd like to make a portable version, but pubuntu looks a bit dated and not so easy to install. Thus I was thinking to use persistence. Not sure how that will do if I try to bulk import drivers and software to it, and also I can't find whether persistence is supposed to be for using the same computer, or whether it would cope being started one day on my 64bitAMD and the next on my Dual Core Centrino.
I've managed to make a 2GB Casper file for this as I'll need some space.

b) P-Qemu seems to be the thing I am looking for (thank you for suggestion of Virtualbox, but I think that needs to be installed fully in windows to be used as I recall the driver install was messy at times on my other machine). But could it work being plugged in to a) above?

As you can see the idea is to have access to my progs and files where ever I go- although I realise I will probably need Admin rights to run p-qemu.

If you could expand a bit on whether you think this is possible using pqemu that would be great.