This happend to me a month ago I got a trojan virus off of limewire. I got rid of it though, if I we're you got to pcpitstop.com and download the scan thing and it should delete it. and to help get Zonealarm anti-virus, it finds it and tells if you have it or not. If it is a Trojan virus it'll be in a windows folder, under system32 or somthing.