making boot from previous internal drive now external work

[Sean Miller]

Right, a bit of background.

Until about 3 weeks ago I had a Toshiba Laptop and I had it on dual boot 
with Windows XP and Hoary Hedgehog.

Unfortunately the laptop expired and so what I did was remove the hard 
drive, put it in a little "caddy" and it is now an external drive -- all 
well and good! :-)

I have now got a new laptop and left the drive connected last night and 
this morning when I booted up the screen said "GRUB" and hung.

I quickly realised that it was trying to boot from the external drive, 
and that got me thinking. I would really like to try booting into the 
external hoary from this new laptop. It would be a great solution to my 
wife's reluctance to let me dual boot her new "toy" (I'm currently 
running Warty in VMWare but that is not ideal).

Now, I'm sure it must be quite easy to modify the boot record on the 
external drive to go straight into Ubuntu (or via GRUB - not an 
issue)... to my way of thinking there are two problems at present...

a) The boot record on the external drive presumably instructs grub to 
look for its config at a location which is currently the internal drive 
in the new laptop. So that needs to change.
b) The grub config on the external drive will presumably also refer to 
physical locations that are inside the new laptop.

So we presumably need to modify the boot record and modify the grub config?

Anybody here got any advice on doing this? Help would be much appreciated.

Sean