After using NOD32 for a year, I decided to go back to freeware and downloaded AVG 9.0. The installation process detected my ZoneAlarm, warned that there could be conflicts with AVG, and strongly recommended that I remove it. I thought it would be a good opportunity to try Comodo, so I replaced ZA with it. When I tried to install AVG again, it gave the same warning about Comodo. I don't buy it (more to the point, I'm not about to buy the AVG security suite over this dubious warning), so I want to try another antivirus. I'm thinking about Avast, but I also noticed that Comodo offers a free antivirus. Have you tried Comodo's antivirus or heard anything about it? Also, while searching TechSpot for answers to my questions, I found a post in which somebody said that Comodo slowed down his Internet connection. Is this a common observation? Any word about ZoneAlarm vs. Comodo (effectiveness, stability, light on resources)?