Trojan Horse was found in my systems. Norton Support, via phone, spent 4 hours to remove it. They scanned, and nothing was found they said. Hired cpu tech who found the Horse, he had to take my laptop and clean it. He's returned it and says the Horse is gone, but why didn't my Norton Internet/virus find it in the first place? Why didn't Norton support find it? I'm very confused and upset. Why didn't Norton find it and how can I use my Norton to find a virus and horse?