You have a small LAN connecting to the Internet through a Modem come router with several ports on the back of the router which every computer plugs into right?
You have added the Netbeui Protocol to your system and can not access the shares on the remaining computers but they can access the shares on yours is this right?
Now are you seeing a My Network Places on the Start Bar under My Computer? But you can print to networked Printers. so at least that part is working properly.
If the above configeration is correct all that should be needed is to run the Network Setup Wizard Change from existing Netorking to New Network and then tell it durring the setup that this computer connects directly to the Internet and others connect through this computer then enable File & Printer Sharing and on the screen when you get to it type in the same workgroup name as the others are running on and then it's just a matter of clicking on next till the thing is finished and runs through a setup procedure for any shares that you have established and ends with the option of making a Network Setup Floppy which you just chose no to.
Reboot and run the computer for a short time and see if the other computer shares appear in your My Network Window
If they don't click on the start Button and then Open Network Connections if it's on the start menu or the Control Panel and then Network Connections and right click on the actual LAN Connection select Properities and look at what is actually installed in the way of existing Networking Protocols at the very least these should be present
Client For Microsoft Networks
File & Printer Sharing for Microsoft Networks
QoS Packet Sceduler
Network Monitor Driver
Microsoft TCP/IP ver 6
Internet Protocol [TCP/IP]
If these are not all there you have missed something in the original setup and it's probably that you have chosen that this computer connects to another or a Residentual Gateway which is causing the problem. If this is the case all you need do is rerun the Network Setup Wizard and setup a new Network Connection and [b]Do Not[/b] chose to use the existing Network connection that is your first option.
Lets know how you get on.
Col