There are plenty of posts (I would guess at least a thousand) in this forum on getting just a network going. The following has been posted many times and makes a good starting point...
The following requirements must be met to browse the Network Neighborhood/My Network Places (share files and printers):
1. You must have at least one of the NetBIOS protocols installed. The NetBIOS protocols are: NetBEUI, IPX/SPX, and TCP/IP. If TCP/IP does not work by itself, go to Start, Setting, Control Panel, Network, select the instance of TCP/IP bound to the network adapter for your local network, Properties, Bindings and be sure the Client for Microsoft Networks and File and Printer Sharing check boxes are checked. They should not be checked for any network adapters used to connect to the Internet.
2. All of the computers must be running a common protocol.
3. You must login to Windows or the Microsoft Client for Windows.
4. A unique computer name must be specified in Network configuration
5. The workgroup name must be specified in Network configuration and should be the same as the other workstations.
6. File and Print Sharing must be installed to see yourself in Network Neighborhood
If File and Print Sharing is not listed in Network Configuration on other peers/workstations then you will not be able to view that machine in Network Neighborhood.
7. If the above requirements have been met, disable or enable Browse Masters. A computer that is infrequently used should not be a Browse Master. There must be at least one Browse Master.
See http://duxcw.com/digest/Howto/network/net2pc/intro.htm for installation details and for instructions on sharing files and printers. Also, Windows help is useful.
If all else fails, install the NetBEUI protocol in addition to the TCP/IP protocol.
Also, the NICs might look like they are properly installed, but may still not operate. Try swapping PCI slots. If your motherboard has a VIA chipset, download and install the VIA 4-in-1 drivers (http://www.viatech.com/drivers/index_new2.htm ), in particular, the IRQ Routing INF. Windows 98 has a problem sorting out interrupts for network adapters plugged into MVP3 motherboards without VIA IRQ routing. Some motherboards have a CMOS Setup setting that should also be changed to VIA routing after the inf is installed. Larry