Yes, it is possible to full automate the process by putting the sequence of steps into Autoexec.bat on your DOS boot. However, before you do anything else, you need to boot to DOS on your parents' machine and make sure you can see the hard disk from DOS. If not, you either need to check the bios hard disk settings for "compatibility mode" and enable that, or use WinPE instead of DOS, adding the appropriate Vista 32 bit drivers for the SATA chipset on their machine.
Alternatively, you might want to investigate the option of providing a recovery partition on their machine in the way that most laptop vendors now ship their machines. This tends to use the imagex.exe that is part of WinPE instead of Ghost, but no doubt you can choose whichever you prefer.