Are all the computers getting interent through the router? Can you ping the computers from eachother? What OS are they running? All XP? Home? Pro? Are they all in the same Workgroup(this is found in properties of My Computer on the Computer Name Tab) Is file sharing enabled on all the machines? If using XP pro is it set to Simple filesharing, if not you'll need to set proper permissions. Are there any firewalls? If any firewalls are running, shut them off until you get the network up, then set proper permissions for sharing.
BTW, with all those extra NICs, make sure you don't have any of them bridged, this could cause you some problems since you aren't doing anything that could possible need a bridged connection. Any bridges you find will be called something like "MAC Bridge Mini-port" uninstall them from device manager and NEVER run any network wizard in Windows again.
Also, going wireless isn't going to be any different except that you won't have the wires, and will have added problems from possible interference. If you can't get it set up wired, it ain't going to work wireless.
When I set up a network, I always connect everything hardwired, make all configuration changes, then disconnect the wires, set up all systems wireless, adjust settings as needed for firewalls and such, make sure everything still works wireless, then secure the network.