Grzyb wrote on 2023-06-14, 04:16:

Double check the IRQ settings...
Re: Cant connect my Windows 95 machine to my home network

Yup, you were right from the start. It was an IRQ problem. I hadn't tried IRQ 5 because my sound card is there (shows up on that IRQ in POST, so I have zero idea how to change it).
The diagnostic tool simply detected it there, and everything worked. Changed it in windows and temporarily disabled the sound card: I have a ping to the router.

Thanks everyone for your help! I learned A LOT. I hadnt' played with an ISA card in so long, I forgot some basic rules (remove all hardware and just leave the problematic one was one of them).