Thanks to all. My basic idea was to update my operating system as much as possible, then burn it to CD using ghost. I then thought that if anything went wrong, or I changed my computer, I could simply restore the ghost image.
I think, as others above have said, the ghost image will install itself on other size hard drives, so that would not be a problem. I also thought that, with a plug and play system, the drivers for basic hardware would be picked up and installed automatically when the image was booted up.
I am going to download the Deploy Tools from Microsoft and have a look at them.
It looks as if True Image has some good reviews, so I might also have a look at it.