I am using Windows Vista operating system with Avira antivirus and my browser is IE8. My desktop has been infected with PWS:Win32/Zbot.DW and the the antivirus that I am using in my system alerted me about this a couple of days ago. The problem is that I am not able to remove this infection with the help of the antivirus. So, I need a method for its removal from the system. Is there any technique to stop them from entering the system? Kindly reply with suitable suggestions.