Workgroup Issue

W98 doesnt have any permissions only sharing options read, full and no access. try removing all the components from network neighborhood like the client adapter and protocol(s). I'm not sure what protocol you're currently using but make sure its thesame on all the systems. I would suggest netbeui since it doesnt require configuration. After removing all the components reboot and reload it again with only netbeui as a protocol. Make sure Netbeui is also loaded on one other system in case Tcp/ipis your primary protocol. make sure to add file & print sharing and share the folders. If that still doesnt do it there must be a problem with some other windows files that support the networking. runs SFC and scan for altered files.
Good luck

Try to remove all the network component like the tcp/ip, netbeui, ipx and the others. then add again the tcp/ip and other protokol you are using. then set the promary logon to microsoft networking as the default logon.
After that restart and try to logon.

If not success, try to ping the machine from other pc. If it respons then it's not a problem with your network. by the way, do you already try to ping it?
other solution is use winipcfg and check the configuration. Check if the ip is setup or auto but you must have a dhcp server.

thank u, good luck