Answers:
If this is a conventional Norton installation disc (not factor of a volume license), you can install it on another computer and afterwards progress to Norton's website to purchase a unsullied subscription. Basically, to be precise what you are buying, a subscription to virus definition updates.
Good luck!
just use one and the same one but avoid the updates and you'll be fine
buy it again
You will hold to buy a up to date disk.
it depends on the license, if it is a broad-spectrum license (unlimited installations) it doesnt event. Most CDs are licensed to be installed on 3 computers which mechanism you are okay. If that doesnt work lately install Norton on your other computer, and buy another subscription, you dont enjoy to buy another disc (that costs more than buying another subscription)
i bought norton internet warranty 2007 and installed it on mine and 2 of my mate computers!! no problems!! works and up date foolproof!!