Ethernet Connected but No Internet, 8-Step Windows Troubleshooting Guide (Before Unplugging the LAN Cable)

You plug in an Ethernet cable, and the network icon clearly says “Connected.”

But your browser won’t load.
Your company messenger shows “No Internet Connection.”

Most people immediately assume:

  • “The cable must be bad.”

  • “The LAN port is dead.”

In reality, Ethernet issues are far more often caused by IP settings, proxy leftovers, or adapter misconfiguration than by faulty cables.

Follow these steps in order.
They are optimized for real-world Windows troubleshooting.

1. Verify Whether the Issue Is Device-Specific or Network-Wide

Before touching any settings, isolate the problem.

How to test

  • Plug the same Ethernet cable into another PC

  • Plug a different Ethernet cable into your PC

Results

  • ❌ Other devices also fail → Router / switch / building network issue

  • ⭕ Other devices work → Your PC’s configuration is the problem

👉 This single step usually determines the entire direction.

2. On Office or School Networks, Check for a Hidden Authentication Page

Wired networks often require authentication.

Examples:

  • Internal login portals

  • Security agents that must run first

  • Network Access Control (NAC)

📌 Open a browser and try visiting any site.
If a login page appears, complete it before proceeding.

3. Confirm That Your PC Received a Valid IP Address (Critical)

A wired connection without a valid IP cannot access the internet.

How to check

  1. Open Command Prompt

  2. Type:

ipconfig

  1. Look for IPv4 Address

Red flag

169.254.xxx.xxx

This is APIPA, meaning your PC failed to obtain an IP from the router or switch.

📌 If you see this:

  • The issue is usually upstream

  • Check router, switch, or wall port power first

👉 If your Wi-Fi also shows “connected” but fails to load pages, this guide may help:
[Wi-Fi Is Connected but There’s No Internet – Wi-Fi Is Connected but There’s No Internet]

4. Release & Renew IP, Flush DNS, and Reset Winsock

(Run as Administrator)

This combination is far more effective than rebooting.

Run in order:

ipconfig /release
ipconfig /renew
ipconfig /flushdns
netsh winsock reset

What this does:

  • Reassigns your IP

  • Clears corrupted DNS cache

  • Resets Windows’ network socket system (Winsock)

⚠️ Note:
Winsock reset requires a reboot and may sign you out of some network-related apps.

5. Make Sure a Static IP Isn’t Still Configured (Very Common)

This is the most common cause on laptops used in offices or schools.

Check here

  • Network Settings → Change adapter options

  • Ethernet → Properties

  • Internet Protocol Version 4 (IPv4)

Correct setting

  • ⭕ Obtain an IP address automatically (DHCP)

  • ❌ Manually assigned IP

👉 A leftover static IP will block internet access on other networks.

6. Check Proxy Settings (Hidden Saboteur)

Even if VPN is off, proxy settings may still be enabled.

Path

  • Settings → Network & Internet → Proxy

  • Turn OFF:

    “Use a proxy server”

Malware and broken VPN clients often leave this enabled silently.

7. Check Network Adapter Settings

(Power Management and Speed & Duplex)

Since you’re already in Device Manager, check both settings.

A. Power Management

  • Device Manager → Network adapters

  • Ethernet adapter → Properties → Power Management

  • Uncheck:

    “Allow the computer to turn off this device to save power”

This is especially critical on laptops.

B. Speed & Duplex (Advanced but Very Effective)

If Ethernet shows “Connected” but speed is near zero or drops randomly, this is often the cause.

Where to check

  • Same adapter → Advanced tab

  • Find Speed & Duplex

Recommended approach

  • First, ensure it is set to Auto Negotiation

  • If the issue persists, temporarily set it to:

    100 Mbps Full Duplex

💡 Why this works:

  • Old routers, long cables, or damaged cables sometimes fail 1Gbps negotiation

  • Falling back to 100Mbps restores stable communication

👉 If internet suddenly works at 100Mbps, your cable is likely degraded.

8. Beginner-Friendly Option: Use Windows Network Reset

If command-line tools feel intimidating:

  • Settings → Network & Internet

  • Advanced network settings → Network reset

This:

  • Removes and reinstalls all network adapters

  • Requires a reboot

  • Resets Wi-Fi passwords

👉 Sometimes the network is fine, but the browser is the bottleneck.
[Google Chrome Suddenly Feels Slow?-5 Things to Check Before Clearing Your Cache]

Final Thoughts

Ethernet problems rarely start with the cable.

Most real-world cases come down to:

  • IP misconfiguration

  • Proxy or VPN leftovers

  • Network adapter power or speed negotiation issues

📌 Key takeaways

  • “Connected” does not mean “communicating”

  • Speed & Duplex mismatches can silently kill traffic

  • Administrator-level resets solve most stubborn cases

If this is a corporate environment, complete these steps before contacting IT.
You’ll either fix it—or speak their language immediately.

👉 Network issues often affect printers and USB devices as well.
[Printer Connected but Not Printing – 9 Things to Check Before Reinstalling Drivers]

👉 A Korean version of this guide is also available for readers who prefer Korean.
[유선 LAN은 연결돼 있는데 인터넷이 안 될 때 – 랜선 뽑기 전에 반드시 확인해야 할 8단계 점검 가이드(윈도우 기준)]