Maybe not entirely relevant to Linux Mint but I'll write this anyway as it allowed me to install a Linux OS.
Whilst in Windows I put my Ubuntu DVD in the DVD drive. When it autoran I noticed an option to "Load Ubuntu in Windows". I used this particular option and it installed wonderfully - certainly no ??? ??? text boxes which occurred when I tried to install from within a DVD LinuxMint/Ubuntu boot system. I now have a dual boot system and I am happily going to familiarise myself with Linux.
I don't think such an option existed on the LinuxMint DVD (could be wrong) but I'm happy enough.
Thanks again for everyone's ideas.