I solved it by switching to Windows Defender (if I recall, it was McAfee rather than AVG). I doubt, on balance, it's any better or worse but doesn't require an annual subscription (not especially cheap either). Security is mostly the product of commonsense, though I'll admit, if it's my parents, that's easier said than done. I lost the will to live just trying to explain the padlock 'secure' option next to the URL. Mind you, these are people that leave the doors open because they're just taking the dog for a walk/going to the shops etc.