All you need to do is select custom instead of typical during install then you can choose what you want to install. You will also be able to choose what file associations you want or do not want for Nero.
I hate Nero 7, the custom install is not exactly simple. If you miss one checkbox it will hijack all of your file associations. I still think Nero 6 is one of the best apps out there and Nero 7 is one of the worst.