How to Fix Slow WiFi on Windows 11 After a Major OS Update: Driver Conflicts, NetAdapter Reset, and TCP Offload Fixes

You install a major Windows 11 update, reboot, and suddenly your WiFi is crawling — pages that used to load instantly now spin, video calls stutter, and a speed test confirms you’re getting a fraction of your normal throughput. This is a well-documented pattern, with Windows 11 24H2 being a notable offender. The update can corrupt the TCP/IP network stack, swap in a mismatched adapter driver, or change TCP offload settings that then tank performance. The good news is that every one of these causes has a specific fix.

Step 1: Confirm the Update Is the Cause

Before diving into fixes, confirm your timeline. Open Settings → Windows Update → Update History and note the date of the last major update. If your WiFi slowdown started within a day or two of that date, the update is almost certainly responsible. Also run a speed test at wifispeed.com on both your Windows 11 PC and another device (phone, tablet) on the same network at the same time. If the phone gets full speed and the PC doesn’t, the problem is definitely on the Windows side — not your router or ISP.

Step 2: Reset the Network Stack (Winsock + TCP/IP)

This is the single most effective fix for post-update WiFi slowdowns. A major Windows update can corrupt the Winsock catalog and the TCP/IP stack — the core layers Windows uses to send and receive data. Resetting them clears that corruption without affecting your saved WiFi passwords or network profiles.

1. Press Windows + S, type Command Prompt, right-click it, and select Run as administrator.
2. Run each command in order, pressing Enter after each one:

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

Restart your PC after running all five commands. This sequence resets the Winsock catalog, clears the TCP/IP route table, releases and renews your IP address, and flushes the DNS cache. Many users who reported near-unusable speeds after the Windows 11 24H2 update on Microsoft’s community forums fixed the issue with this step alone.

Step 3: Fix TCP Receive Window Auto-Tuning

Windows 11 uses a feature called Receive Window Auto-Tuning to dynamically size the TCP receive window for each connection. Some major updates misconfigure this setting, which can throttle download speeds dramatically on fast connections — the effect is especially visible on connections over 100 Mbps.

In an elevated Command Prompt, check the current value:

netsh interface tcp show global

Look for the Receive Window Auto-Tuning Level line. If it says disabled or highlyrestricted, reset it to normal:

netsh interface tcp set global autotuninglevel=normal

Restart and retest. This command specifically resolved severe slowdowns on high-speed adapters reported after Windows 11 24H2, where auto-tuning had been silently set to disabled by the update.

Step 4: Disable Large Send Offload (LSO) on Your WiFi Adapter

Large Send Offload v2 (LSO) is a feature that lets the network adapter handle TCP segmentation in hardware rather than the CPU. On paper this improves performance, but after a Windows update the LSO driver can become mismatched, causing the adapter to segment packets incorrectly and slow throughput to a crawl. This is particularly common with Intel and Realtek wireless adapters on Dell, HP, and Lenovo laptops.

To disable it:

1. Press Windows + X and open Device Manager.
2. Expand Network Adapters and double-click your WiFi adapter.
3. Go to the Advanced tab.
4. Find Large Send Offload V2 (IPv4) and set its value to Disabled.
5. Find Large Send Offload V2 (IPv6) and set its value to Disabled.
6. Click OK and restart.

You can also do this in PowerShell if you prefer:

Set-NetAdapterAdvancedProperty -Name "Wi-Fi" -DisplayName "Large Send Offload V2 (IPv4)" -DisplayValue "Disabled"
Set-NetAdapterAdvancedProperty -Name "Wi-Fi" -DisplayName "Large Send Offload V2 (IPv6)" -DisplayValue "Disabled"

Replace Wi-Fi with the exact adapter name shown in Device Manager if yours differs.

Step 5: Roll Back or Update the WiFi Adapter Driver

Windows Update sometimes installs a generic Microsoft-supplied network driver over the manufacturer’s tuned OEM driver, or pushes an adapter driver version that has known bugs. Either way, the driver mismatch shows up as degraded speeds.

Option A: Roll Back the Driver

1. Open Device Manager → Network Adapters.
2. Double-click your WiFi adapter and go to the Driver tab.
3. Click Roll Back Driver if the button is available. This restores the previous driver version.
4. Restart and retest.

Option B: Install the Manufacturer’s Latest Driver

If rollback isn’t available or doesn’t help, download the latest driver directly from the chipset manufacturer:

• Intel WiFi adapters: Intel’s support site lists the latest Intel Wireless Adapter Software drivers. Search for your adapter model (e.g., Intel Wi-Fi 6E AX211).
• Realtek adapters: Download from the Realtek website or your laptop manufacturer’s support page (Dell, HP, Lenovo support sites carry tuned builds).
• Qualcomm/MediaTek adapters: Use your PC manufacturer’s support page for the correct build.

Uninstall the current driver in Device Manager first (check “Delete the driver software for this device”), restart, then install the downloaded driver.

Step 6: Use Windows’ Built-In Network Reset

If the above steps haven’t resolved the issue, Windows 11 has a full network reset option that reinstalls all network adapters and reverts all networking components to their defaults. It’s more thorough than the command-line resets in Step 2.

1. Open Settings → Network & Internet → Advanced Network Settings.
2. Scroll down and click Network Reset.
3. Click Reset Now and confirm. Your PC will restart automatically.

Note that after a network reset you’ll need to re-enter saved WiFi passwords, and any VPN software will need to be reinstalled. Weigh this against the severity of the slowdown before proceeding.

Step 7: Prevent Windows From Reinstalling a Bad Driver

After you’ve installed a working driver manually, you may want to prevent Windows Update from overwriting it again. Open Settings → Windows Update → Advanced Options → Optional Updates and uncheck any driver updates for your WiFi adapter. Alternatively, use the Group Policy setting Do not include drivers with Windows Updates (available in Windows 11 Pro and Enterprise) to block driver updates through Windows Update entirely while still receiving security patches.

Quick Checklist

1. Verify the PC is slower than other devices on the same network
2. Reset Winsock and TCP/IP stack (netsh winsock reset, netsh int ip reset)
3. Flush DNS and renew IP (ipconfig /flushdns, ipconfig /renew)
4. Set TCP auto-tuning back to normal (autotuninglevel=normal)
5. Disable Large Send Offload V2 (IPv4 and IPv6) in adapter advanced settings
6. Roll back or reinstall the WiFi adapter driver from the manufacturer
7. Use Windows Network Reset as a last resort
8. Block Windows Update from reinstalling a bad driver

Post-update WiFi slowdowns on Windows 11 almost always trace back to one of three root causes: a corrupted network stack, a misconfigured TCP setting, or a driver mismatch. Work through the steps above in order and you’ll isolate the culprit quickly. For related guidance, see our article on WiFi slow after a Windows update and our explainer on how internet speed actually works.