Fix Network Stack Buffer Overflow on Windows 10/11

Quick Answer

Run netsh int ip reset and netsh winsock reset in admin Command Prompt, then reboot. That clears the overflow 9 times out of 10.

What's Actually Happening Here?

Your network stack has a small buffer that holds data packets as they come in. When something goes wrong — bad driver, massive traffic spike, or a buggy app — that buffer fills up faster than it can empty. Windows sees this and throws the dreaded "buffer overflow detected" error, usually with code 0x800705b4. Your internet just dies. I saw this last month on a client's Dell laptop running Windows 11 after they installed a cheap VPN. The VPN's driver was flooding the stack with junk packets. Another guy I helped had it on a HP desktop after a Windows update broke his Realtek network driver. The fix is the same: clear the stack and reset the components.

Fix Steps: Clear the Buffer Overflow

1. Open Command Prompt as Admin — Search for cmd, right-click, choose "Run as administrator".
2. Reset Winsock — Type netsh winsock reset and hit Enter. This wipes the socket catalog and forces a clean slate.
3. Reset TCP/IP Stack — Run netsh int ip reset. This rewrites TCP/IP registry keys and resets the stack.
4. Flush DNS — Type ipconfig /flushdns. Clears old cached entries that might be part of the problem.
5. Release and Renew IP — Run ipconfig /release then ipconfig /renew. This gets you a fresh IP from your router.
6. Reboot — Restart your machine. The stack needs a clean start.

After reboot, check if the error's gone. Most of the time, you're back online. If not, move to the alternative fixes.

Alternative Fixes If the Main One Fails

Fix 1: Disable and Re-enable Your Network Adapter

Go to Control Panel > Network and Sharing Center > Change adapter settings. Right-click your active adapter (Wi-Fi or Ethernet), choose Disable. Wait 10 seconds, then right-click and Enable. This forces the driver to reset its internal buffers. Quick and dirty, but works when the stack reset doesn't.

Fix 2: Update or Roll Back Your Network Driver

Open Device Manager, expand Network adapters, right-click your adapter, select Properties. Go to the Driver tab. If you just got a Windows update, click Roll Back Driver. Otherwise, click Update Driver and let Windows search. I had a case where a Intel Wi-Fi 6 driver from 2022 was causing the overflow — rolling back fixed it instantly.

Fix 3: Increase the Network Buffer Size via Registry

This is for advanced users who keep hitting the overflow. The default buffer size is small. You can increase it:

reg add "HKLM\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters" /v "TcpWindowSize" /t REG_DWORD /d 65535 /f

Then reboot. This sets the TCP receive window to 65535 bytes, giving the stack more room. I don't recommend going higher than 65535 on most home networks — bigger isn't always better and can cause packet loss on some routers.

Fix 4: Remove Problematic Software

If the error started after installing something — VPN, network monitoring tool, or even a game with anti-cheat — uninstall it. I've seen Valorant's Vanguard anti-cheat mess with the network stack on Windows 10. Uninstall it, reboot, and see if the overflow stops. You can always reinstall later if needed.

Prevention Tip: Stop It From Coming Back

The real fix is keeping your network drivers updated. Don't rely on Windows Update alone — it's slow. Go to your motherboard or laptop manufacturer's site and grab the latest network driver directly. For Realtek, go to their official site. For Intel, use their Driver & Support Assistant tool. Also, avoid those free VPNs and network "optimizers" — they're often the ones causing the buffer overflow in the first place. If you do use a VPN, stick to well-known ones like ProtonVPN or Mullvad that don't install crapware drivers. One more thing: if you're on a public Wi-Fi (coffee shop, hotel), the buffer overflow can happen from network congestion. In that case, just disconnect and reconnect — no driver changes needed.