after dabbling with various security apps, from AVG, NOD32, Comodo (the Firewall and malware suite), and a few others I cannot remember, I've grown weary. Comodo was my last one, I just liked the whole package. But the heuristics drove me nuts, found so many things that are known to be safe.
I'm done with heuristics. It's nice as it CAN find new things before updates are found, but... all the extra resources required for these 3rd party apps, plus the heuristics, I'm done.
Basic windows firewall, and Microsoft Security Essentials, is doing the trick for me, after installing Windows 7 figured it would be enough for me. Between ADP and NoScript on firefox, and just in general being smart about system use, I cannot imagine I'll be running into a problem. Haven't had real malware in forever due to better habits. I do my part, and these Microsoft methods will help if I slack.