First, check the physical connection by reseating or replacing the Ethernet cable and testing on another device; 2. Disable power saving for the Ethernet adapter in Device Manager to prevent Windows from turning it off; 3. Update, roll back, or reinstall the network driver via Device Manager or the manufacturer’s website; 4. Adjust advanced adapter settings by disabling Energy Efficient Ethernet, Green Ethernet, Flow Control, and Interrupt Moderation, and set Speed & Duplex manually; 5. Reset network settings using Command Prompt with netsh and ipconfig commands; 6. Ensure Windows and security software are up to date and test for conflicts via clean boot; 7. Consider updating BIOS/UEFI firmware if all else fails; most issues stem from settings or drivers, not hardware, and following these steps typically resolves the disconnection problem.

If your Ethernet adapter keeps disconnecting in Windows, it can be frustrating—especially if you rely on a stable wired connection. The good news is that most of these issues are fixable without needing new hardware. Here’s a step-by-step guide to diagnose and fix the problem.

1. Check the Physical Connection and Hardware

Before diving into software fixes, rule out basic hardware issues:

• Unplug and reseat the Ethernet cable at both ends (computer and router/modem).
• Try a different Ethernet cable—a damaged cable is a common cause of intermittent disconnections.
• Plug the cable into a different port on your router or switch.
• Test the connection on another computer to see if the issue follows the cable or port.
• If using a USB-to-Ethernet adapter, try a different USB port or adapter.

If the problem doesn’t occur on another device, the issue is likely with your computer.

2. Disable Power Saving for the Ethernet Adapter

Windows sometimes turns off the network adapter to save power, which can cause disconnections.

Steps:

1. Press Win X and select Device Manager.
2. Expand Network adapters.
3. Right-click your Ethernet adapter (e.g., "Realtek PCIe GbE Family Controller") and select Properties.
4. Go to the Power Management tab.
5. Uncheck "Allow the computer to turn off this device to save power".
6. Click OK.

This is one of the most common fixes—many users report their disconnections stop after disabling this setting.

3. Update or Reinstall the Network Driver

Outdated, corrupt, or incompatible drivers can cause instability.

Option A: Update via Device Manager

1. In Device Manager, right-click your Ethernet adapter.
2. Select Update driver > "Search automatically for updated driver software".

Option B: Download from Manufacturer

• Go to your PC or motherboard manufacturer’s website.
• Look for the latest network/Ethernet driver (e.g., Realtek, Intel, Killer).
• Download and install it manually.

Option C: Roll Back or Reinstall Driver

• If the issue started recently, try rolling back the driver in Properties > Driver tab.
• Or uninstall the driver, restart your PC, and let Windows reinstall it automatically.

4. Adjust Ethernet Adapter Settings

Some advanced settings can interfere with stable connections.

Steps:

1. In Device Manager, right-click the Ethernet adapter → Properties.
2. Go to the Advanced tab.
3. Look for these settings and try changing them:
   • Energy Efficient Ethernet → Set to Disabled
   • Green Ethernet → Set to Disabled
   • Speed & Duplex → Instead of "Auto-negotiation", try setting it to 1.0 Gbps Full Duplex (or match your network capability)
   • Flow Control → Try Disabled
   • Interrupt Moderation → Set to Disabled

Changes here can stabilize the connection, especially on older or mixed network hardware.

5. Reset Network Settings in Windows

Corrupted network configurations can cause recurring drops.

Steps:

1. Open Command Prompt as Administrator (Win X > Terminal (Admin)).
2. Run these commands one by one:

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

3. Restart your computer.

This clears out potential TCP/IP stack issues.

6. Check for Windows Updates and Conflicting Software

• Make sure Windows is up to date—some network bugs are fixed in updates.
• Temporarily disable third-party antivirus, firewalls, or VPN software that might interfere.
• Check if the problem occurs in a clean boot (using msconfig) to rule out software conflicts.

7. Consider BIOS/UEFI and Firmware Updates

In rare cases, outdated motherboard firmware can cause hardware-level network issues.

• Visit your motherboard or PC manufacturer’s support page.
• Check for BIOS updates that mention network or USB/Ethernet fixes.
• Follow instructions carefully when updating BIOS.

Final Thoughts

Most recurring Ethernet disconnections in Windows come down to power management settings, faulty cables, or outdated drivers. Start with the simple fixes—swap the cable, disable power saving, and update the driver. If those don’t work, tweak the advanced adapter settings and reset the network stack.

If the problem persists across multiple cables, routers, and even after a clean Windows install, the Ethernet port itself may be failing—consider using a USB-to-Ethernet adapter as a workaround.

Basically, it’s usually software or settings—not the hardware.

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