Greetings,
As long as you have the Product Activation Key, you can install the program from whichever means you aquired it, whether it be via CD or downloaded from the Internet.
If you don't have the installation files available, you can
download trialware versions of our programs, which will be unlocked once you install it and enter your Product Activation Key.
If you are not certain what your Product Activation Key is, it may be saved in your
Norton Account if you created one.
Further information on the Norton Account can be found in this
Knowledge BaseDoes this answer your question, or was there another detail that I'm missing?
Thanks!