We had to buy new network cards and hub. The cards we used earlier were 10/100 Pine cards. But the curious thing is that none of the new cards are working anymore. We tried various brands of 10/100 cards but to no avail. Then my partner tried 10 Base T cards and horray! The systems are now seeing themselves. But the problem is that up till now, three systems are not on the network no matter how I try. It is like there is a limit to which number of systems can be on the network. One system keeps telling me that "You are not authorized to access so and so system, see the network administrator.." something to this effect. I know there is security built into XP. How do I get around this? I will be grateful if you kindly help me out.
The first thing I would do is to buy a UPS for your networking equipment and surge protectors for all computers. Plugging your computer into the wall without a surge protector is like driving through the city without car insurance.
It sounds like you may have replaced your hub with a 10baseT hub and not a 10/100 hub. Also, you may have a cable plugged into the incorrect port of the hub, which will disable all equipment (See your hub manual for instructions). I would start with basic TCP/IP to troubleshoot this. Plug one PC into the Hub at a time. Make sure all computers are on the same subnet (IE. Set comp1 IP address to be 192.168.1.1, mask 255.255.255.0 and comp2 IP address to 192.168.1.2, mask 255.255.255.0 etc). If your computers are not on the same subnet they will not be able to talk to each other. Plug a second PC into the hub and see if you can ping back and forth. If you can ping the other machine then the Hub, NIC and wiring are correct. Continue until you find a problem machine.
The XP issue sounds like you are not configured as a local admin on the computer. Open up "users and computers" and add yourself to the computer as a local admin. Remove the NIC and re-add it.
This was first published in August 2002