Naismith
Charter Member
Just use Microsoft's anti-virus. It works fine. Anything it doesn't pick up will likely be attributed to ignoring basic security, such as opening files from unknown sources, etc. Supplement it with a program like Spybot and you'll be good, and there will be no cost. I've used this setup for years and I've never contracted a virus.
Edit: everyone always has an opinion, as you can see. I still recommend using Microsoft's anti-virus. Unlike all of the other ones you'll hear recommended, the layout hasn't changed in about ten years, is completely free, works just fine, and takes up almost no resources. Some will claim it will miss certain viruses, but I've seen it catch things others won't (tit for tat). Frankly put: It. Just. Works.
Seconded! I've been using MS Essentials for years now and never been infected. It's caught a few in the years. Also I use Malwarebytes when I can remember.