Hi penguin247,
After all the uninstalls and reinstalls, please tell us how you uninstalled/reinstalled - such as removed via Control Panel (with or without a reboot), did you save your settings for the reinstall, where did you get the reinstall from (downloaded, disk or Norton Account).
One thing to try is open N360, select Support and the Subscription Status - do this in each user.
Let us know what happens in each user and how many days are displayed after the status check on each user.