Installing NIS 2011 - 2 questions.

I have two questions on installing NIS 2011.

 

1) I presently have NIS 2011 Trial version installed on my main PC. I have purchased a retail copy of NIS 2011 for 3 PC's. I have read that the Trial version is the full version and if that is correct can I just enter my new Product Key to activate without having to reinstall from the CD?

 

2) I plan to install NIS 2011 on a 2nd PC. Is it better to use the CD or download NIS 2011 from the website and use the Product Key from the CD?

 

I have 20 days left on Trail version so it is still active.

 

Thanks,

Jim