If you have multiple computers in your home and you are not sure which one may be infected, instead of connecting your computer to the internet via the wireless gateway or home router, connect each one separately to the cable modem one at a time. Once an individual computer is connected to the cable modem, go to
http://www.dns-ok.us. If you get a green page back, the connected computer is OK; if you get a red page back it is infected.