Windows 11 update on Aug 25 crashed my system,lost Internet connection

Since the PC shows Ethernet as connected but browsers and Windows Update cannot reach the internet after a Windows 11 update, use this order of troubleshooting:

1. Check the physical connection again.
   • Make sure the Ethernet cable is firmly connected to both the PC and router.
   • On the router, confirm the cable is in an Ethernet/LAN port, not the modem/router Internet port.
   • If possible, try a different Ethernet cable.
2. Run the Windows network troubleshooter.
   • In Windows 11, open the Network and Internet troubleshooter in the Get Help app.
   • This runs diagnostics and can automatically fix common connection problems.
3. Try the same network on another device.
   • If another Windows PC with Ethernet can connect, the problem is likely on the affected Dell.
   • If another device also fails, the issue is more likely the router, ISP, or adapter/cable.
4. Run the network reset commands as administrator.
   • Open Command Prompt as administrator.
   • Run these commands in this exact order:
     • netsh winsock reset
     • netsh int ip reset
     • ipconfig /release
     • ipconfig /renew
     • ipconfig /flushdns
   • Then test browsing and Windows Update again.
5. Reinstall the Ethernet adapter driver.
   • Warning: this temporarily removes network access until restart or driver reinstall.
   • Before uninstalling, download the latest Dell network adapter driver on another PC if needed.
   • Open Device Manager > Network adapters.
   • Right-click the Ethernet adapter > Uninstall device.
   • Select Attempt to remove the driver for this device > Uninstall.
   • Restart the PC.
   • Windows should reinstall the adapter automatically. If not, install the backup driver downloaded from Dell.
6. Use Network reset only as the last step.
   • Warning: this removes and reinstalls network adapters and resets their settings to default.
   • It can also require reinstalling VPN software or virtual switches, and may change known networks to Public.
   • In Windows 11: Start > Settings > Network & internet > Advanced network settings > Network reset > Reset now > Yes.
   • Restart and test again.
7. If the issue started immediately after the August update and the steps above do not fix it, uninstall the recent update from recovery.
   • Remove unnecessary external devices first.
   • Force entry into Windows Recovery Environment by interrupting startup three times.
   • In Choose an option, go to Troubleshoot > Advanced.
   • Use Uninstall Recently Installed Updates.
   • If needed, use System Restore to return to a restore point from before the issue.

This pattern matches known post-update cases where the network adapter or its driver stops working correctly even though Windows still reports a connection.

• Fix Ethernet connection problems in Windows
• Troubleshoot problems updating Windows
• Internet connection lost during windows update installation - Microsoft Q&A
• KB5086672 Update broke Internet and Ethernet - Microsoft Q&A