I believe that this is called "hostageware". Norton has a long history of doing this. Whenever I get my hands on a new system that comes preloaded with Norton software I hack it out asap. The same is true for any McAfee software. In any event, after you have uninstalled the program you have to also disable the product from running when Windows starts. While it can be disabled in the Startup Tab by running msconfig and the Taskmanger it is easier to use a good, valid, and highly effective freeware program like Ccleaner. You can get the portable version here https://www.ccleaner.com/ccleaner/download/portable
Once installed run Ccleaner and select the Tools section then click on the Uninstall option and see if Norton is listed. Unistall and Delete it from your system. Then select the Startup section, find the offensive program and select Disable then Delete. Next select the Cleaner section and select Registry and scan and clean the registry entries. Reboot and run Ccleaner again to check to see if Norton has reinstalled itself in the Startup section.