Please read this first if you have a network problem

In my experience there are two truths to network problems

1. The most common source of networking faults is the physical connection
   
2. The first thing most users do when they get a network fault is to start trying to reconfigure the software (drivers etc.). This often introduces new problems without fixing the underying problem

• If your network connection fails the first thing to check is the physical connection. Almost all network connections have an LED on the network card and a corresponding one on the switch/router/hub and one is also present on many wireless cards. This should flash irregularly but fairly often. If the LEDs for your connection is not lit the most probable cause is either a cable problem or a fault at the switch/router/hub. If you find this, turn off the switch/router/hub (switch off the power if you can't find a switch on the unit). If this doesn't fix the problem try another cable.
  
  If you want to avoid scambling around the back of your PC to look at the LEDs, you can cheat and jump to the next test (however if this second test fails you'll then need to start that scrabbling).
  
  
• The second test is to check that everything is working at the IP level. This is one of the most basic levels of networking. Most other networking tasks build on the platform of being able to connect at the IP level. To test that everything is working at this level open a command shell (Run > "Command ") and type:
  
  PING <IP Address>
  
  Where <IP Address> is a remote IP address on your network. The best to start with is your ISP's DNS server's IP address. If you can ping that address (you will get replies), everything is working at the IP level and you can move onto the next test.
  
  
• If this fails, try pinging your own address. You can find your own address by typing IPCONFIG at the command prompt. If you get replies but cannot get replies from other IP addresses on the network check you address matches the rest of the network. You can use this tool to check that your IP address matches the IP address of the local PC or device you are trying to connect to. Change the IP to one that matches the others on the network if it is wrong. If you are using automatic address, the problem is probably a network fault between you and the device you are trying to connect to. Check you cables and connections.
  
  
• If you can't ping your own IP try 127.0.0.1 (PING 127.0.0.1). This address is a special "loopback" address. Basically it tests your TCP/IP system without testing the network card. If both these fail you have a problem with TCP/IP or your network card settings. Delete the TCP/IP service (from the network connection properties), reboot, and then reinstall them. If that doesn't fix the problem try deleting the network card in Device Manager and reboot. The drivers should reinstall on boot. If that doesn't work try new drivers. Then try another network card.
  
  
• If you can ping by IP address, the next step is to try pinging by name. Try pinging a well known web site (e.g. PING www.windowsbbs.com - however be aware this may fail if the internet is busy) or even better ping your ISP's mail server (often mail.ISPName.net), these are relatively close to you on the internet and less likely to time out. If this fails you probably have a name resolution problem.
  
  To test you name resolution at the command prompt type:
  
  NSLOOKUP www.windowsbbs.com
  
  You should get a response that tells you the IP address of this remote system and the DNS server that has given you this address. If this fails you have a DNS problem. Check that your DNS is set to either your intenet router's IP address (common set up with Broadband routers - won't work on big networks); your network's DNS server's IP address; or your ISP's DNS server's IP address.
  
  
• If some NSLOOKUPs work but others fail, or you can ping your internet router but not beyond, the next thing to try is a TRACERT. Try:
  
  TRACERT www.windowsbbs.com
  
  If you get a response from your internet router but no further, you have a problem with the router. Check that it is connecting to the internet. See if other PC get further (it could be a routing problem on the router or a firewall rule that is blocking your connection).
  
  If the tracert route gets further (the next address will be the first of your ISP's routers) and then fails, the problem is with you ISP's system. Ring their technical support and read your TRACERT readout to them.
  
  
• If pinging by IP address and by name works but you cannot see other computers in network the problem is probably with network neighbourhood. It is very unlikely that it is physical network problem or a driver problem.
  
  One problem with network neighbourhood in XP is that if you have no shortcuts in your network neighbourhood, with the default set up nothing else appears. Network neighbourhood appears empty. This is "normal ". To see the rest of the network you have to find the "Entire Network" icon and double click on that. You will then be able to drill down into the network. You can see "Entire Network" if you click on the "Folders" Button in network neighbourhood (you may have to click on the plus sign next to the network neighbourhood icon).
  
  
• If drilling down takes a long time, try typing:
  
  \\<computer name>
  
  in the address bar. That shoud take you straight to the computer you are trying to connect to. If you have got this far and all the other test have been passed, the problem is most likely permissions. You need to have an account on the computer you are trying to connect to, and that computer must be sharing files. Go to this link to find information on how to set up folder sharing in Windows XP.
  
  
• If you get this far and are still not getting anywhere you may have a firewall problem. Check your firewall settings. One way forward is to switch off the firewall and rerun the tests. If everything now works, you know the problem is with the firewall. However, nowadays running without a firewall is not to be advised. So check the settings thoroughly and avoid turning off the firewall. If you have a broadband/internet router and your problem is connecting to a local computer on your network, disconnect the router from the internet before turning off your system's firewall. If your a network admin, try another firewall rather than running without a firewall.

 

It is important to know that the TCP/IP protocol cannot be removed in Windows XP. It is considered the core component. However, you can reset TCP/IP. For more details, see the following Microsoft Knowledge Base Article.

How to reset Internet Protocol (TCP/IP) in Windows XP
http://support.microsoft.com/default.aspx?scid=kb;en-us;299357

 

There goes one of my "old reliables ". Shows how rarely I get network connections faults that turn out to be the card-TCP/IP. Well that's my excuse and I'm sticking to it.

Thanks for the ammendment.

 

It also important to know that disabling firewalls doesn't always work. You can try disabling first. The only way to be sure is to uninstall them while troubleshooting the network.

Personal Firewall Interferes with Windows Networking
http://www.practicallynetworked.com/support/personal_firewall_prob.htm

Remove All Firewall Programs While Troubleshooting
http://www.practicallynetworked.com/sharing/troubleshoot/removefirewall.htm

 

Discussion does bring up something relavant.

TCP/IP in XP and a Firewall.

The LAN was all setup and working a LLLOONNGGGGG time before I even thought of such a thing as a Firewall. Maybe that is why I never had a problem with the Firewall and Networking.

This PC has been on a LAN since the EARLY days of 98SE.

BillyBob