USB identical to my desktop ... How

Hi forum,
I am trying to get a USB boot identical to the system I installed on my desktop. I was able to boot on a laptop with no problem after having made the USB boot key but it's like the CD version. Meaning no changes I made on the desktop has been saved for the USB boot. So the question is, is it possible to have like a mirror of a desktop or would we be limited to a copy of the ISO CD ?
Thank you all for your help.

Sebastien.

[soad1982.blogspot.com]

I found this. I only tried it out to the point of running usb-bootable-elive in a root terminal but that worked

Quote

Replace 1024 with the sice in MegaBytes you want.

Our persistent file is ready we just need to modify the boot file on our USB to use this file, edit: