After installing Windows update KB5089549, multiple laptops are facing severe website connectivity and performance issues.

Question

Issues observed:

• Websites loading very slowly
• Some websites not opening
• Teams and Outlook not working properly
• Issue occurs on different Wi-Fi networks as well
• Not limited to Lenovo devices; observed on multiple laptop models

Troubleshooting already performed:

• Uninstalled updates
• Reset network settings
• Reinstalled network drivers
• Tested with different Wi-Fi networks

The issue still persists and is affecting daily work activities. Is anyone else facing the same issue after KB5089549? Any official fix or workaround available?Issues observed:

• Websites loading very slowly
• Some websites not opening
• Teams and Outlook not working properly
• Issue occurs on different Wi-Fi networks as well
• Not limited to Lenovo devices; observed on multiple laptop models

Troubleshooting already performed:

• Uninstalled updates
• Reset network settings
• Reinstalled network drivers
• Tested with different Wi-Fi networks

The issue still persists and is affecting daily work activities. Is anyone else facing the same issue after KB5089549? Any official fix or workaround available?

Answer 1

Héllo Arun Kumaresh,

While you have already performed standard network settings resets, the graphical interface often fails to clear deep system corruption introduced by cumulative updates like KB5089549. You must execute a manual rebuild of the Windows Sockets API and TCP/IP stack using an elevated Command Prompt. Running the command netsh winsock reset directly targets and clears corrupted catalog entries located within the registry at HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Winsock and Winsock2, which act as the core database coordinating your network software. Following this, executing netsh int ip reset rewrites the essential IPv4 and IPv6 configuration keys, stripping away any misconfigurations causing Teams, Outlook, and your browsers to stall. Finally, running ipconfig /flushdns clears the local resolver cache, forcing the system to pull fresh routing data from your DNS server.

If executing these commands and rebooting your device does not restore stable connectivity, the issue is an OS-level regression hardcoded into the update itself. Because this network failure impacts multiple device manufacturers and distinct wireless environments simultaneously, local troubleshooting has reached its limit. You will need to monitor the Microsoft Windows Release Health dashboard for your specific operating system build. Microsoft handles widespread update regressions by issuing an Out-of-Band patch or initiating an automated Known Issue Rollback to silently revert the problematic network code. Waiting for this official engineering resolution is the only compliant and secure path forward for your affected fleet.

Hope this answer brought you some useful information. If it did, please hit “accept answer”. Should you have any questions, feel free to leave a comment.

VPHAN

Answer 2

I have experienced the similar problem in few of Windows 11 computers. I have uninstalled KB5089549 that fixed the internet slow down, remote desktop connection and performance issue of machine.

Answer 3

Hi Arun Kumaresh,

How is your issue going? Has it been resolved yet? If it has, please consider accepting the answer as it helps others sharing the same problem benefit too. Thank you :)

VPHAN