Norton 360 will not launch

When I tried to launch Norton 360, after waiting a while, I am told to use the Norton Removal & Reinstall Tool. 

I have also tried using the Windows 10 uninstall tool before using Norton Removal & Reinstall Tool. 

After reinstalling, I can launch Norton 360 and live updates and then a full system scan.

Do malware, viruses, etc. is found. When do shutdown my computer my ability to launch Norton 360 goes with it.

Do I need a new computer at this point. Some experts on cyber security tell me that no anti-virus product can fully protect your system.

After 3 to 5 years of internet surfing, I am told that a new computer is needed as the old one to too infected.

Is there anything else I can do???