You're welcome to live with your head in the sand, but I can tell you with 100% certainty that your system could be compromised in less than 5 minutes. It has nothing to do with a virus or malware. Viruses and malware are passe. They're not used by criminal enterprises.
If you have SSLv3 or TLSv1.0 enabled on your machine (I'd bet the farm you do), it's trivially easy to get into your machine.
If you have a printer attached to your machine, directly via USB or via network, it's trivially easy to compromise your system through the spooler.
If you have off-the-shelf retail network hardware such as a router/switch combo made by Linksys, NetGear, or TP-Link, I would take a Vegas bet that the firmware is out of date and full of security holes.
Win7 is one part of a larger security perimeter in your home environment. The OS is the last stop for an attacker, and using a deprecated OS means you're essentially leaving a welcome mat at the front door with the key dangling from the door handle. Relying on third party "security" suites is foolhardy and is 100% NOT going to protect you.
Norton protection for Windows 7 once Microsoft ends its support
Even your antivirus vendor is advising you to upgrade!
What’s “SSLv3 or TLSv1.0”?
The router is an xfinity (Commiecast) unit, and is updated weekly, I’ve been told. I ditched the Linksys years ago.
Many thanks for the sage and appreciated advice, but I’m staying w/ Win-7. Everything important is moved onto external ‘My Book’ drives, and is also backed-up to another WD external drive.