3Com NIC’s wont see the network

I have been playing with this system for a few weeks. I am trying to connect it to the peer to peer network. I recently installed the 3Com 16port hub with nic’s, no prob. But when I tried to add another system, no luck. I even went to the extreme ofchanging the motherboard & cpu. I have also tried 2 different nic cards without success. Changed the PCI slot, reinstalled software and the only error that has been given was that the EMM386.EXE installed will not allow the NIC to operate. This is anew 1 for me. Does anyone have any idea about the EMM386.EXE file in windows 98 SE.