wpegg: To my understanding, Win 7 extended support ends on 14th Jan 2020, until then you'll get all security updates. After then it would be foolish to keep using that OS for your mainstream use such as internet browsing, as you'll be vulnerable to drive by attacks exploiting vulnerabilities that will no longer be patched.
So basically: By 2020-01-14 either move to Linux, or move to Win 8+ (if you can get win 8, realistic view is you have to take Win 10).
Tauto: So,even a good AV wont cover what windows would normally update,then it's time they did as it's an easy out for them.
AV's do their best, but ultimately if you're running an insecure OS, you're in trouble. Keep in mind that your AV has to run "inside" your OS, so is only able to stop threats once they get beyond that boundary. If there are fundamental OS issues they can't help. Sorry, but my original advice stands (though ZyloxDragon makes a point)
Themken: I also wonder is there is an upgrade path anymore, paid or not.
Not to the casual user. Business might be able to negiotiate extended support as they did for XP, but us mere mortals have a defined lifespan.
EDIT: Upgrade path - yes, I think win 7 will upgrade to Win 10.