Can someone explain this to me. What layers should I have in my defense? I have Nortons Internet Security and a firewall router on a cable internet connection. How can I configure all this to "prevent" intruders. I have posted the "Many Trojans" post in the other area. I love to download little programs for ripping mp3's or misc. apps for tinkiering with windows. How can I prevent trojans and viruses? I obviously had the trojans on my system before installing Nortons Internet Security because it never detected anything ever. Never a virus or trojan. I used Spybot 1.3 and never had issues other than some small spywear. I always found with spybot and removed and imunized. Now my system is sitting idle. Running Windows XP pro.