Fix 'ERR_CONNECTION_RESET' in Chrome on Windows 10/11

Quick Answer

Run netsh int tcp set global autotuninglevel=disabled in an admin Command Prompt, then restart Chrome. 8 times out of 10, that's it.

What's Actually Happening

ERR_CONNECTION_RESET means Chrome sent a SYN packet to the server, the server responded with SYN-ACK, but before the final ACK handshake completes, something on your machine kills the connection. The server sees a RST (reset) packet, and Chrome throws this error. This isn't a server problem — it's your local network stack or a security tool stepping in.

I've seen this trigger when Windows 10's TCP auto-tuning feature gets aggressive with certain routers (especially older TP-Link or Netgear models), or when a third-party antivirus (looking at you, Norton and McAfee) decides the TLS handshake looks suspicious. It also happens if you have a misconfigured proxy or a broken VPN extension.

Fix Steps (in order of likelihood)

1. Disable TCP auto-tuning
   Open Command Prompt as Admin. Run:
   netsh int tcp set global autotuninglevel=disabled
   Then netsh int tcp set global chimney=disabled
   Reboot. Chrome should be fine now. What's happening here is that Windows tries to dynamically adjust the receive window size during the TCP handshake. On some routers, this sent a malformed window scale option that the router couldn't handle, so it sent a RST.
2. Reset Winsock catalog
   If step 1 didn't work, run in same admin CMD:
   netsh winsock reset
netsh int ip reset
   Reboot. This rebuilds the entire network stack. It fixes issues where a previous VPN client or malware left hooks in the Winsock catalog that interfere with new TCP connections.
3. Temporarily disable firewall or antivirus
   Disable your third-party antivirus entirely (Windows Defender is fine). Test Chrome. If it works, you need to add Chrome as an exception in your AV's HTTPS scanning settings. Don't just disable it permanently — that's asking for trouble.
4. Clear Chrome's SSL state
   Go to chrome://settings/security, scroll to Advanced, and click Manage certificates. Then go to the Trusted Root Certification Authorities tab and remove any weird-looking entries (especially ones from your AV). Then go to chrome://net-internals/#sockets and click Flush socket pools. Then restart Chrome.
5. Disable proxy settings
   Open Windows Settings > Network & Internet > Proxy. Turn off Use a proxy server. Sometimes a leftover proxy config from a corporate network or a bad VPN extension forces all traffic through a dead endpoint, which resets connections.

Alternative Fixes (if the main ones fail)

• Reset Chrome flags — go to chrome://flags, click Reset all to default. Some experimental network flags like #enable-quic or #enable-parallel-downloading can cause this error on certain ISPs.
• Run Chrome with no extensions — shift+right-click the Chrome icon, select properties, add --disable-extensions to the target field. If the error stops, you've got a rogue extension. I've seen ad blockers and VPN extensions cause this when they trip over certificate validation.
• Flush DNS and reset Chrome's HSTS — Run ipconfig /flushdns in CMD. Then go to chrome://net-internals/#hsts and delete the domain you're having trouble with. Sometimes Chrome remembers an old HSTS policy that no longer matches the server's certificate.

Prevention (so it doesn't come back)

• Keep your router firmware updated. I've seen a single router firmware update fix this permanently on three different machines.
• Uninstall third-party antivirus that does HTTPS scanning. Windows Defender is good enough for 99% of users, and it doesn't mangle your network stack.
• Don't install browser toolbar extensions or VPN extensions from unknown developers. They often inject themselves into the network layer.
• If you use a corporate VPN, make sure it's the latest version and run the VPN's own network repair tool (most have one).

One last thing: if this error only happens on one specific website (like a bank or school portal), it's not your machine — it's the website's SSL termination being weird. Try Chrome's --ignore-certificate-errors flag for a quick test, but never browse with that flag on permanently.