Hi I have a downloader.trojan in my computer, and I ran the AVG free edition on my computer an it couldnt remove it, is there any other software that can do it? o how can i do it? Thank a lot

You can try Trojan Remover. Otherwise, you should be using a good commercial antivirus program (there are better ones than AVG) and a decent firewall with anti-spyware/malware protection.