There is no amount of application security, NT or otherwise, that will prevent you from receiving viruses on a Windows machine. They come as an attachment some people actually inadvertently run, or even as a TEMPORARY INTERNET FILE off of a site you may visit, without you even knowing, and do not need for you to run them for them to do what they are going to do. Some just report back to the person's server information about you, like what sites you've visited from your history logs, and don't affect applications or application security at all. Some disrupt network communication - which can affect ANY computer, not just Windows PCs. To say that NT application security will protect you is definitely a giving in to a false hope, especially without a firewall that lets that nasty traffic right in. Have fun getting your trojans.