installing backtrack from a usb external hard drive through ubuntu 9.10

[Kms1974]

I'm trying to install backtrack to a ubunto computer from an iso I copied from my dvd to my external hard disk. Here is the problem, the external hard disk will only be recognized when ubuntu is running. Since it is an older computer, I can't boot from my USB external hard drive (or the usb port period). how do I install backtrack from the external hard drive using ubuntu? Any ideas?

[Snayler]

Burn it to a DVD and install from there. I think there's also a version of grub that allows you to boot from an ISO image.

[Kms1974]

i"m sorry, i forgot to mention that this computer doesn't have a dvd player. Its only capable of reading and burning CD's it a dell insperion 8200.

[Snayler]

Then take a look at this.

[xX_Spiidey_Xx]

alternatively, you can pare down the iso so that it will fit on a cd; but i _really_ only recommend that you do this if you _know_ what you're doing.
some basic instructions on how to customise your iso can be found here.