STATUS_CONNECTION_RESET (0XC000020D) – Fix the reset connection error

1. Firewall or security software is blocking the connection

This is the number one cause. Nine times out of ten, 0XC000020D pops up because your firewall – Windows Defender Firewall or a third-party suite like Norton, McAfee, or Kaspersky – decides the connection looks suspicious and cuts it. The error often shows while trying to connect to a remote server, an FTP site, or a game server. You'll see it in event logs as TCP connection reset.

Here's the fix:

1. Press Windows Key + R, type wf.msc, and hit Enter. That opens Windows Defender Firewall with Advanced Security.
2. In the left pane, click Inbound Rules. Wait for the list to load (it can take a few seconds).
3. Look for any rule that blocks the program you're trying to use. Sort by Name or Program if you have a lot of entries.
4. Right-click the rule and choose Disable Rule. Don't delete it – you might need it later.
5. Now go to Outbound Rules and do the same thing. Many connection resets are blocked on the outbound side.
6. If you don't see a specific rule, check the Action column. If it says Block and the connection matches your program's port, disable that rule.
7. Still stuck? Temporarily turn off Windows Defender Firewall entirely: go to Control Panel > Windows Defender Firewall > Turn Windows Defender Firewall on or off, select Turn off Windows Defender Firewall for both private and public networks. Do this only to test – turn it back on afterward.
8. Test your connection. If the error disappears, you've found the culprit. Re-enable the firewall, then create an allow rule for your program instead of keeping the firewall off.

After disabling the blocking rule, you should see the connection go through without the error. If it still shows up, move to the next cause.

2. Antivirus real-time protection is intercepting the TCP handshake

Antivirus software often acts like a man-in-the-middle for network traffic. It inspects every packet, and sometimes it decides a particular packet is invalid and sends a TCP RST (reset) packet. This triggers 0XC000020D. I've seen this happen with Avast, Bitdefender, and even Windows Defender's own network protection.

The quick test:

1. Right-click your antivirus icon in the system tray (near the clock).
2. Look for an option like Disable, Pause protection, or Turn off real-time scanning. Choose a short duration – 10 or 15 minutes.
3. Try your connection again. If the error doesn't show, you've found the problem.
4. Now you need to create an exception for the program. In your antivirus settings, look for Exclusions, Allowed programs, or Exceptions. Add the full path to the program's .exe file.
5. Also add the port numbers the program uses (check the program's documentation). Common ports are 80, 443, 21, 22, 3389.
6. Re-enable real-time protection and test again.

If the error still appears after disabling antivirus, it's probably not the antivirus. Move on.

3. Stale network drivers or corrupted Winsock stack

This cause is less common but still pops up after a Windows update or a driver update gone wrong. The network driver doesn't handle TCP properly, or the Winsock catalog (which tells Windows how to handle network calls) gets corrupted. You'll see the error on any program that uses the network, not just one specific app.

Fix it in three steps:

Step 3a: Reset Winsock

1. Open Command Prompt as administrator. Press Windows Key + X, then click Command Prompt (Admin) or Windows Terminal (Admin).
2. Type netsh winsock reset and press Enter. You'll see a message that says Winsock was reset successfully.
3. Type netsh int ip reset and press Enter. This resets the TCP/IP stack.
4. Restart your computer. After the restart, test your connection.

Step 3b: Reinstall your network adapter driver

1. Press Windows Key + X, choose Device Manager.
2. Expand Network adapters. You'll see your Wi-Fi or Ethernet adapter listed (something like Realtek PCIe GbE Family Controller or Intel Wi-Fi 6 AX200).
3. Right-click the adapter and choose Uninstall device. Check the box that says Delete the driver software for this device if it appears.
4. Restart your computer. Windows will automatically reinstall the driver during boot.

Step 3c: Update the driver manually

1. In Device Manager, right-click the network adapter and choose Update driver.
2. Select Browse my computer for drivers, then Let me pick from a list of available drivers on my computer.
3. If you see multiple versions, pick the newest one. If that doesn't work, try an older one – sometimes new drivers cause this problem.
4. Restart after the update.

Quick-reference summary table

Start with the firewall fix. It's the fastest and most common. If that doesn't do it, kill the antivirus temporarily. If you're still stuck, reset the Winsock and drivers. In my experience, one of these three always kills 0XC000020D.