I'd comment, but I don't see the wiring, if there is a router and your pest control methods.
I have a fairly new HP with XP and most of the peripherals, also another computer along side on the same cable.
My computer seemed to go dismo on me, so restored it to a previous date. I thought I had it but, no web service.
I also ran safe mode, ( which I have never really understod too well). Changed the cables back and forth, shut down several times, hoping it would reset.
Too much time on it and no results. I would call my I ISP, but the other computer works fine.
Throw anything at me, I will try it, even if I already have. Have checked other answers on your line, but did not find one which addressed this exact problem.