I've been there and learned a valuable lesson, use Carbonite to backup important files and use nothing but Webroot Secure Anywhere which has the anti virus, spyware and everything in one. The others like norton and Mcafee don't hold a candle to it. You can buy and download right on line or buy at most Walmart stores or best buy. I've done computer work for 20 years and it has never failed me. I've had people go against my recommendation only to come back at some point in the future to have me fix their computer and install Webroot. It will give you peace of mind with the Webroot and Carbonite combo.
Good luck!