A client system was plagued by WindowsAntivirus2009. Modified the Nod32 v3 scan options to include Potentially Unwanted Applications. A full system scan and didn't even find the virus and/or malware, even though popups and other obvious infections are bouncing all over the screen. It took a program titled SuperAntiSpyware to detect and remove the infection. How can the best antivirus software not catch this?