Use NIS 2009 product key for NIS 2010?

I bought a retail (boxed) version of NIS 2009, but cannot install it on Win7 (incompatible). Now that NIS 2010 is released, how (or where) can I download the full package without having to deal with "opt-out trial version"?  I've never use the product key, so I understand I can use it for NIS 2010?