There are several reasons why I can't dual boot.
I am going to try to very gently introduce the computer's "Windows7 enthusiast" owner to Linux and see if it will get him to consider changing.
In my opinion, him being able to boot into Windows as usual and then select Mint as what you might call 'an ordinary program' is better than his using Grub.
Secondly, he has a most peculiar inurance on the computer. The insurance company has taken over the 2 year warranty from the manufacturer. The insurance states that he can, in effect, do nothing to the machine apart from such every day things like plugging periferals in and installing standard software. Oh, and using the rescue partition. In theory, I can't even remove the side panel to clean inside the machine. Anything else has to be done by one of their chosen registered computer engineers. So, we think that me installing another operating system and dual booting will void the warranty and insurance. We are certainly not going to the expense of getting their engineer to modify the hard drive. He probably has never heard of dual booting and wouldn't know what to do!
The owner is against me messing about with his hard drve as well, in case it destroys his Windows installation.
So, Mint4Win is the only solution.
Hope I have made this clear.