Network connectivity issues in Windows XP SP2 can stem from various sources. There may be a problem with the dynamic allocation of IP addresses, the network layer, or a faulty configuration of the WEP/WPA security keys in the computer's system.
Once you have identified where the problem comes from, it has a fairly simple fix. This article includes tips on how to solve some of your network issues with Windows XP SP2.
You may be experiencing a problem with the dynamic allocation of your IP address (DHCP). Check whether the DHCP service is enabled on your router and the DHCP client is enabled under Windows Services.
To access Windows Services, go to Start > Run, and then type services.msc.
N.B. Check that your firewall is not inhibiting this process. If you still have not been able to fix the connectivity issues, try manually assigning the IP address.
Network Detected but No Connectivity
If the local network warns of limited or no connectivity, then you can change your settings, so that you are notified each time that this becomes an issue.
Go to Start > Control Panel > Network Connections. Right-click on the connection, and choose Properties.
In the configuration window, uncheck the Notify me when this connection has limited or no connectivity option.
Problem with the Network Layer
Sometimes, limited or no connectivity is caused by a problem with Windows' network layer. You can fix this by reinitializing the network layer.
Go to the start menu, and select Run. Type cmd, and click OK.
For Windows 2000/ XP SP1, type netsh int ip reset all to reset the IP. For Windows XP SP2/Vista, type netsh int ip reset all followed by netsh winsock reset catalog.
Restart your computer and you should be able to connect.
Problem Related to WiFi
Limited or no connectivity on a WiFi network may be due a faulty configuration of the WEP/WPA security key. If the key is incorrect, the connection will still be settled, but the encryption will be different between the modem and your computer. This will stop data exchange from being established, thus causing limited or no connectivity.