Today I opened an email from classmates.com and got a Trojan. My defenses alerted me to it, it flashed?

Question

twice and I have not seen it since. I updated and ran Avast, AdAware Personal, Spybot, Superantispyware, and CCleaner.They all came up empty.
Has the trojan been eliminated or is it hiding somewhere?If it is hiding what else can I do to find it?

Also Microsoft firewall and a hardware firewall in a router are in place.

Answer 1

If everything signals all-clear and the defenses spotted it in the first place, I'd breathe a tentative sigh of relief.