Microsoft Security Essentials built into Windows 7, and allowed to update itself, is all I use. And seem to need.
Earlier OS's were vulnerable but this alone seems to be sufficient now. Oh and Adblock Plus on this home PC, UBlock Origin on the ranch laptop. They seem identical in effect.
I get a 'Don't Open That!' or 'Don't Click That Link! warning once in a while, less than one per year, and that's as close as I've come to problems.
The only incident I recall that I had to really dig into like I did back in the days when I did PC support, turned out to be a 'feature' in TBN: 'Harbor Freight' in a post caused a strange reaction. It turned out that TBN earned cash from HF every time HF was mentioned, and my ISP had a filter that detected these redirects and popped up an ominous red Warning!!! screen for every mention. After tracing the HTML it turned to to be 'a feature, not a bug'. My ISP soon quit throwing up that warning, I think after the link-bonus company got themselves out of some virus database. Aside from that incident I don't recall anything since I upgraded from XP several years ago.
Summary: Avoid McAfee and Norton, use one of the other free AV's if you think you need it, don't worry.
Oh - and obvious: avoid the default add-ons when you install or update software - the 'Ask' search engine etc.
