This error always annoys me whenever I come across it, but sometimes on a Domain Network, you will come upon a machine that will be unable to identify the network and won’t be connected to the internet or the network share folders. Follow these steps while logged in as an administrator to get it back on the network.
1.) Disable any and all third party firewall programs.
Antivirus and anti-malware programs have their own inbuilt firewalls. To disable then, you need to go to Services (best accessed through MSCONFIG, search for it in your Start menu). Uncheck all the boxes for firewall services there. Sometimes this will do the trick, if not, continue to step 2.
2.) Ensure your drivers are up to date.
Sometimes if the security parameters for the network are updated, and your Network Card drivers are not up to date, you need to update your drivers. To do this, open up Device Manager (which can be done from the Start menu and typing devmgmt.msc). In Device Manager, expand Network adapters, then right click on the card that your Ethernet cable is plugged into. Open Properties, and select the Driver tab. From there, you can select the Update Driver option if there is a newer driver available. Alternatively, you can delete the network card’s driver, then right click Network adapters, and tell it to Scan For Hardware Changes and it will pick up the card and install the latest driver available for that card. This second method is a bit of overkill, so only resort to this if the first one isn’t working.
3.) Flush and renew your DNS
Open command prompt, and enter the following commands in order below hitting enter after each one:
1: ipconfig /registerdns
2: ipconfig /release
3: ipconfig /renew
4: netsh winsock reset
Reboot once these commands are done.
4.) Restart your router and modem
If you got this far and are still experiencing issues, it could be an issue with the router and modem. This is tested by restarting them. Do not reset it by pushing the button, we want to reboot the router and modem, not restore them to factory settings. Just unplug, and wait 30 seconds, then plug back in.
5.) Check Adapter Settings
Open Network and Sharing Center, then click Change Adapter Settings. First ensure that any network that you are not trying to connect to is disabled, then right click on the network you are trying to connect to, and select Properties. Highlight Internet Protocol Version 4 (TCP/IPv4), then select properties. Ensure that both the Obtain IP Address Automatically and the Obtain DNS Server Address Automatically options are checked, then select ok.
If you got this far and still haven’t reached a resolution, then there is probably an issue or defect with the physical machine itself that you will need to contact it’s manufacturer about. Issue the user an alternative machine for the time being, and check to make sure the machine is under warranty. There could be something really kooky that is throwing it off (once, I had a machine that wouldn’t work until I started the Wired AutoConfig service in services), but 9 times out of 10 when you get to this point, it’s no longer worth the time to investigate before contacting the manufacturer because it’s most likely a physical defect with the machine.