After Windows 11 update the internet connection via ethernet keeps dropping

Question

After Windows 11 update the internet connection via ethernet keeps dropping.

Update (2025-10 Cumulative Update for Windows 11, version 25H2 for x64-based Systems (KB5066835) (26200.6899) performed on October 15, 2025

Is there a way to solve this? I have tried to disable the power savings settings for the network adapters and USB root power settings but did not help.

Thanks in avance for your help.

Answer 1

Hi PapaoDaMasta, Thanks for posting here in Microsoft community, The KB5066835 update for Windows 11 (25H2) is causing widespread issues with Ethernet and local IIS services. Since you've already tried disabling power-saving settings, here’s what you can do,

First, Update Ethernet Drivers Manually, simply go to your motherboard or PC manufacturer’s site and download the latest Windows 11-compatible Ethernet driver. Install it via Device Manager.

 

Next, Disable HTTP/2 (if IIS or localhost is involved), open regedit, then add these registry keys to disable HTTP/2:

 

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\HTTP\Parameters]

"EnableHttp2Tls"=dword:00000000

"EnableHttp2Cleartext"=dword:00000000

 

Then restart your PC.

Also try to update Microsoft Defender Definitions, some users fixed the issue by updating Defender. Open Windows Security > Virus & threat protection > Check for updates.

Lastly, Rollback the Update (if nothing else works) simply Go to Settings > Windows Update > Update History > Uninstall Updates, remove KB5066835, and pause updates temporarily.

 

I hope this helps you out,

Chard