In the last 12 years that I've owned a pc, I've tried Norton, ESET NOD32, AVG free, Avira free, Avast free. I had run the Avast for several years without any problem, but lately after reading some articles that pointed out that internet vulnerabilities were growing, I thought I'd be smart and try a non free AV. After doing a lot of looking around and reading, I thought I'd give BitDefender a whirl for 30 days. My firewall at that point was Comodo free, and somehow I had forgotten that it had some other security features enabled. So installing BitDefender resulted in several BSOD's. Got it figured out and installed, along with a copy of Zone Alarm to replace Comodo. Initial scan with BD found a trojan that Avast hadn't picked up, so I was feeling lucky. After a couple of weeks, I had noticed 1 or 2 flaky things going on...small but noticeable. I attributed them to recent AV updates, and they disappeared later. Today Firefox became very obstinate and pages didn't want to load. I decided to try to pull some files off my external HD and that became balky. Drive wouldn't appear in My Computer and pc would stall / lock up. OK, that's enough of that. Rip out BitDefender ... problems gone. So I went back and grabbed NOD32...runs just fine. It didn't have the best reviews...good, but not the best. But it runs and doesn't cause issues....yet. I'm curious to see other's experiences with AV and firewalls. After reading lot's of reviews about several products, it always amazes me how a majority can have decent results and a small group will have an abysmal time with same product. After so much reading, you really have no clue what to buy. Anybody else in the same boat ?