If your Ethernet connection is showing "No valid IP configuration" error, it means that your computer is not able to obtain a valid IP address from the network. This can happen due to various reasons such as network misconfiguration, faulty hardware, or software issues. Here are some steps you can take to troubleshoot and resolve this issue:

1. Restart your computer and networking equipment:

Sometimes a simple restart can fix the issue. Restart your computer and also power cycle your modem, router, and any other networking equipment you may have.

2. Check the Ethernet cable:

Ensure that the Ethernet cable is properly connected to both your computer and the networking device. Try using a different Ethernet cable to rule out any issues with the cable itself.

3. Check network settings:

Go to Control Panel > Network and Sharing Center > Change adapter settings. Right-click on your Ethernet connection and select Properties. Make sure that "Internet Protocol Version 4 (TCP/IPv4)" is checked and set to obtain an IP address automatically.

4. Release and renew IP address:

Open Command Prompt as an administrator and type the following commands:

- ipconfig /release

- ipconfig /renew

This will release the current IP configuration and attempt to obtain a new one from the network.

5. Disable and re-enable the Ethernet adapter:

In the Network Connections window, right-click on your Ethernet connection and select Disable. Wait for a few seconds and then right-click again and select Enable.

6. Update network drivers:

Outdated or corrupted network drivers can cause connectivity issues. Visit the website of your computer's manufacturer or the network adapter manufacturer to download and install the latest drivers for your network adapter.

7. Run network troubleshooter:

Windows has a built-in network troubleshooter that can help identify and fix common networking problems. Go to Settings > Update & Security > Troubleshoot, and then select "Internet Connections" to run the troubleshooter.

8. Check for software conflicts:

Sometimes third-party software such as antivirus programs or firewall applications can interfere with network connectivity. Temporarily disable such software to see if it resolves the issue.

9. Reset TCP/IP stack:

Open Command Prompt as an administrator and type the following command:

- netsh int ip reset

This will reset the TCP/IP stack to its default state, which can help resolve IP configuration issues.

10. Contact your network administrator or ISP:

If you are in a corporate or institutional environment, or if you are unable to resolve the issue on your own, contact your network administrator or Internet Service Provider (ISP) for further assistance.

By following these steps, you should be able to troubleshoot and resolve the "No valid IP configuration" issue on your Ethernet connection. If the problem persists, it may indicate a more complex network issue that requires professional assistance.