Thanks. I understand all your answers.
Are you sure the closed laptop was actually online? There can be signs of traffic with a machine turned off. It is the nature of packets trying to connect to destinations. My home pc gets flickering router lights all day long when turned off.
Not sure. I can find out quickly by doing the "unplugged bit", but I need to do a few other steps first, and I don't understand networks well. One red (-?ethernet) cord runs from the webstar cable modem to the wireless zonet router, and the other red line to the fubard laptop). If I unplug the red ethernet from the lap- I'll lose wireless, since the stationary machine- this one has a burnt out port for that and the mother boards are 9 years defunct. I configued the wireless default myself- years ago when I was even dumber and somewhere i read-or was told forcefully- that the enet must be connected and configured to a working computer with the red cord for the wireless to work. It does not have to be on. I do get flicking light below the e-net port- particularly when i start using internet. So truly- the mangled lap is a "dummy machine". & very likely it got virus while turnrd off.