Internet has slowndown considerably after Windows Updates

Question

Details:

I'm using Windows 11 and my computer is up to date as of the recent update on 3/11/2026 (KB5079473), apparently there was an update prior to this (KB5077181) that affects internet speeds. I can't uninstall this update as it's not an option and there has been reports of blue screens and crashes after removing this update. I usually get 200mbps over WiFi out of the 1000 being paid for and the PC isn't close enough to the router for an Ethernet cable so that's out of the question. Now after the Windows updates, I'm currently only getting 10-20mbps on average, maybe 30-40 on a good day. I have tried resetting my computer, the WIFI, forgetting the WIFI, changing the DNS setting, flushing the DNS, all my drivers are up to date, etc. Trying to work is a mess as my browsers take forever to load and my applications take a while to just save progress. Regular games as well, that have online functions are either a stuttering mess or flat-out don't work from time to time, so I can't do anything there either. Question:
I'm looking for a fix to this since this issue only occurred after updating my computer (in reference to details above).

Answer 1

Hi NDYNE,

Thanks for your post. Have you already tried the Q&A Assist suggestions? In addition, please try the following.

Step 1 – Check for Microsoft’s official fix (important)

Microsoft released an out‑of‑band update (KB5085516) specifically to address network and internet‑related issues introduced by KB5079473.

Please check if this update is available on your PC:

1. Open “Settings” > “Windows Update”
2. Select “Check for updates”
3. If KB5085516 is offered, install it and restart

Microsoft confirms this update is intended to correct internet‑related behavior caused by the March update. Official Microsoft update info: March 10, 2026 — KB5079473 (OS Builds 26200.8037 and 26100.8037)

Step 2 – Quick verification to isolate the cause

After installing all available updates:

• Run a speed test immediately after restart
• Then test again after 10–15 minutes of normal use

This helps determine whether the slowdown is tied to the Windows network state rather than signal strength or the router itself.

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Answer 2

Follow these steps on the Windows 11 PC to troubleshoot slow Wi‑Fi after the recent updates:

1. Check Wi‑Fi signal and interference
   • Move the PC as close to the router as possible, even temporarily, and re‑run a speed test.
   • Ensure there are minimal obstructions (walls, large metal objects) between the PC and router.
   • If speed improves significantly when closer, the issue is likely signal strength or interference rather than Windows itself.
2. Close background apps using bandwidth
   • Press Ctrl + Shift + Esc to open Task Manager.
   • Go to the Processes tab and look at the Network column.
   • End or close any apps using high network bandwidth (cloud sync, game launchers, update tools, etc.), then test speeds again.
3. Test the router with another device
   • Connect a phone, tablet, or another PC to the same Wi‑Fi network in the same location.
   • Run a speed test.
   • If speeds are also low on the other device, the router or ISP connection may be the bottleneck and may need maintenance or replacement.
4. Adjust Wi‑Fi power settings (to prevent throttling)
   • Open Control Panel → Hardware and Sound → Power Options.
   • Next to the active plan, select Change plan settings → Change advanced power settings.
   • Expand Wireless Adapter Settings → Power Saving Mode.
   • Set it to Maximum Performance for both On battery and Plugged in.
   • Apply and reboot, then test again.
5. Reinstall the Wi‑Fi adapter driver This can help if the update corrupted or mismatched the driver.
   • Press Search on the taskbar, type device manager, and open Device Manager.
   • Expand Network adapters and locate the Wi‑Fi adapter.
   • Right‑click it → Uninstall device.
   • Check Attempt to remove the driver for this device if available → Uninstall.
   • Restart the PC via Start → Power → Restart.
   • Windows will automatically reinstall the network adapter driver. Test Wi‑Fi speed again.
6. Use Network Reset as a last resort Network reset will remove and reinstall all network adapters and reset network settings to defaults.
   • Open Settings → Network & internet.
   • On Windows 11, select Advanced network settings → Network reset.
   • Select Reset now → Yes.
   • The PC will restart; reconnect to Wi‑Fi and test speeds.
   • Be aware: VPN clients, virtual switches (Hyper‑V, etc.) may need to be reinstalled or reconfigured afterward, and known networks may be set to Public profile.

If speeds remain low only on this PC after all steps above, and other devices on the same Wi‑Fi get normal speeds, the issue is likely specific to this Windows installation and network stack; in that case, continuing with network reset and clean driver reinstall is the most effective built‑in remediation.

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References:

• Fix Wi-Fi connection issues in Windows
• Fix Ethernet connection problems in Windows