First, I have to admit that I am a Linux noob.

What I want to do is to be able to send a "rescue DVD" together with the PCs that I send to my customers. The PCs are setup and tested in each case with specific software.
If something goes wrong at the customer, he shall simply use the rescue DVD to get back to normal. The rescue DVD shall possibly run fully automatically.

Knoppix comes to mind, both for creating the HD image, but also for the recue DVD itself. That Knoppix runs from a CD/DVD is perfect for the job.

How to use Knoppix to create the image ?
How to create a self-booting rescue DVD that automatically restores the image to the HD on the target PC ?

I am thinking that this functionality can be used by many others.
Any input will be much appreciated.