Network Issues: LAN shows connected but not able to connect to internet

If you are faced with a situation where your LAN connection shows "connected", and there are no error notification on the network icon in system tray, but you cannot connect to the internet, then try the following.

Such issues can occur after some system changes were performed either by you or some software in your computer. AntiVirus installation and un-installations can also trigger such issues as it was in my case this time. I had Kaspersky AntiVirus removed and ever since I could not connect to the internet though all my network adapters shows fine.

In this particular scenario, I have a wired connection with a static IP which works on another computer but not on one particular desktop computer running Windows XP.

Preliminary network checks:

Before you go digging, you should check these basic things when faced with network/internet issues.

• Check with another computer on the same network if it is able to access internet. If not check the source (router, modem etc).
• If you are using internet from your router, usually IP address is auto assigned by the router using DHCP. See if it is enabled.
• If using static IP, check in the network adapter's IP  properties if you are using the right IP or if it has reset to auto assign.
• Check your browser's network proxy settings. If you do not connect via a proxy, it should not be checked. 

Generally, if any of the above problems exists, then your network adapter notification area in the system tray will show some indicators.

Check fishy items in network adapter properties:

• Open Control Panel > Network Connections > right-click on the network adapter > properties
• See if you have any fishy items from some software. You will usually see your antivirus program here too. If it is un-installed but still showing here, select and un-install from here also.

Network Adapter Properties

Try Ping
Try pinging "www.google.com". If the ping command fails saying "unable to connect to host" then the problem is not just with the browser but something else. Dig deeper.

To ping do-

• Press Start and in the search box type "run". Press enter.
• Type "cmd" and press enter. A black command prompt window will appear.
• Type "ping www.google.com"

and see the results.

If things are right, you should at least see "pinging ....." and not "unable to connect to host" etc.

Check IP info

• Press Start and in the search box type "run". Press enter.
• Type "cmd" and press enter. A black command prompt window will appear.
• Type "ipconfig /all" - see of any media disconnected or other errors. 

Reset DNS 

From the preliminary checks above, we will now come to know that it is not an issue with your network, IP, browser settings etc. So now try the following commands in a command prompt:

• netsh int ip set dns 
• netsh winsock reset 

You would be asked to restart your computer.
After restarting, check by visiting any site. It should be resolved by now.