Computer crashed, want to install Norton in new computer. Please help

My old computer crashed and i bought a new computer recently. I would like to install my norton to my new computer. I read the Q&A and it says to enter the product key on the site. The thing is, my Norton allows me to install Norton on 4 computers,currently, only 3/4 of my computers have Norton. Im worried if I type out the product key, my new computer will use the 4th Norton. What do I do?


BTW- Im saving the 4th Norton for someone.