HELP! How to remove a trojan?

It keeps popping up system errow. Your system was infected by a dangerous trojan. I have ran avast, nortons, superAntispyware, windows defender, cyber defender,and spyware doctor and they don’t even detect it. But it’s there and very frustrating.
I think golden ray may be right about buying fraudulent applications cause it wants me to purchase antimalware application. problem is i still can’t remove that annowing pop up.

i recommend manual removal of dangerous trojan: http://www.2-spyware.com/remove-dangerous-trojan.html
this way you can be sure that every files related to dangerous trojan is removed.

i must say that Dangerous Trojan comes bundled with several corrupt security tools. its purpose it to scare people and make them buy fraudulent applications. you need to run antispyware scan to delete other computer parasites that comes with dangerous trojan.

windows vista segurança proteja seu pc contra pragas da internet !