Norton renewal

Hi everyone, help or advice please.

 

I am about to renew NIS 2011, I normaly do this on-line, but our local store had the 3 PC, CD version on offer at half price.

Do I need to re-install using the CD or can I just use the product code within the CD cover?

 

PC is a Advent laptop (notebook), Windows Vista, 64 bit.

 

Thanks in advance