I have several computers on my network. All Gateways' (3-6) years old, all xp pro, all connected to one server and behind a physical Esmith firewall. All of sudden the computers randomly started losing then finding their internet connections over and over. I shut down all units and installed a program called "WireShark" on my server. I then turned on the rest of the computers one at a time til I found the problem computer. Apparently it was randomly latching onto IP addresses of other computers causing all the disruptions. I went to device manager of faulty computer, but saw no red or yellow warnings by the NIC. Could just needing to update NIC drivers cause this serious of a problem, or is NIC completely shot? I would greatly appreciate input and suggestions! Thanks, vandal67

NICs can go bad but before you buy anything, look at the event viewer first. Start, run, type eventvwr.msc and press enter.

ok - am I looking for something in particular? thanks, vandal67

yep red or yellow warnings. How did you determine this? "Apparently it was randomly latching onto IP addresses of other computers causing all the disruptions." When you had no popup errors saying duplicate ip? Are you sure you were not seeing a net browser election taking place? If you leave this computer off you have no errors? If you bring the computer up you start having internet fits? Is this computer free of malware and virus's?

I started one computer at a time. The 1st 16 made no change in our ability to get on the internet. As soon as the 17th computer (the one that apparently was causing the problems), the 1st 16 and the server could no longer access the internet. And running an ipconfig on the 17th one, discovered it had the same address as the one assigned to our Esmith firewall. When that 17th computer was shut down, all internet access returned to 1st 16 computers. We started and stopped the 17th computer a few more times with the same results. Afterwards we started the rest of our network computers (60), with no further problems. We found no malware and viruses on the 17th computer. I thought I mentioned the popup duplicate ip errors in my original message, but I see now that I didn't. Sorry. vandal67

What did you use to check the 17th PC for viruses and other malware?

Not a problem vandal67 about the popups. I just go thru a list in my head. Have you looked at the esmith's routers dhcp scope? I am assuming the workstation is clean, is set to get a dhcp address [does not have a static address] and is functioning otherwise perfectly. If this is the case, it's what is giving it that address that is at fault not the client.