This is the 2nd time now I've suddenly gotten a popup screen that says it's from Windows Security and that I'm infected with trojans and must download stuff immediately to take care of it. I always quickly get rid of the pop-ups - the first time this happened I quickly did a full McAfee scan and it showed no problems at all. It would catch it, right? I'm usually pretty skeptical of messages like that, but I do wonder... actually I don't even know what a trojan is. But McAfee total protection should've blocked them anyway, right?