trying to save time and effort

To save time installing knoppix in a lab environment, I have used G4U to copy a good knoppix install to another drive. Most of the time it works to pop the new drive into a PC and boot up. Knoppix usually finds all the new hardware and works fine. I am having a problem with some older monitors though that cannot handle the display settings in X windows. I see in the FAQ there is a solution for adding a new graphics card, by copying over the new display settings from the cd-rom boot up, to the hard drive install. Unfortunately, I have a few older machines that the cd drives do not work very well. Is there a way on a hard drive install to stop the boot process and pass some cheat code commands, so I can boot up successfully, and then make necessary changes in the display settings?