Force Windows 10 to Use IPv4 Over IPv6

If you’re experiencing slow connections, timeouts, or websites that won’t load on Windows 10, a misconfigured or unreliable IPv6 connection might be the culprit. This guide shows you how to prioritize IPv4 over IPv6, either by disabling IPv6 entirely or by tweaking the Windows network stack to prefer IPv4. You’ll need administrator access to your PC.

What You’ll Need

• A Windows 10 PC with administrator privileges.
• Knowledge of your network adapter’s name (e.g., “Ethernet” or “Wi-Fi”).
• Optional: a backup of your registry (Windows will prompt you if you use Registry Editor).

Step-by-Step

Method 1: Disable IPv6 Entirely (Most Effective)

1. Press Windows Key + R, type ncpa.cpl, and press Enter. This opens the Network Connections window.
2. Right-click the network adapter you’re using (the one with a green bar or the one labeled “Connected”) and select Properties. If you’re unsure, check the one that says “Internet access” under the name.
3. In the list, scroll down and find Internet Protocol Version 6 (TCP/IPv6). Uncheck the box next to it.
4. Click OK and then close the window. Windows will momentarily drop the network connection and then reconnect using IPv4 only.
5. Restart your browser and test the connection. If the issue persists, also try restarting your PC to ensure the change takes full effect.

Method 2: Use Registry to Prefer IPv4 (Advanced)

This method doesn’t disable IPv6 but tells Windows to try IPv4 first. It’s useful when you need IPv6 for certain apps but want IPv4 as the primary.

1. Press Windows Key + R, type regedit, and press Enter. If prompted by User Account Control, click Yes.
2. Navigate to the following path in the left sidebar:
   HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip6\Parameters
3. Right-click in the blank area on the right, select New > DWORD (32-bit) Value.
4. Name it DisabledComponents and press Enter.
5. Double-click the new value. Select Decimal and enter 32. This is the decimal value that corresponds to the hexadecimal 0x20, which tells Windows to prefer IPv4 over IPv6. (Other values exist, but 32 is the one you want for this purpose.)
6. Click OK, close Registry Editor, and restart your PC for the change to take effect.

Method 3: Use Command Prompt (Quick Alternative)

1. Right-click the Start button and select Command Prompt (Admin) or Windows PowerShell (Admin).
2. Type the following command and press Enter:
   netsh interface ipv6 set prefixpolicy ::ffff:0:0/96 46 4
3. This command modifies the prefix policy table to give IPv4-mapped addresses a higher precedence (46) than native IPv6 (which is usually 40). It effectively makes Windows prefer IPv4 for most connections.
4. Close the window. The change is immediate; no reboot needed. To revert, run:
   netsh interface ipv6 set prefixpolicy ::ffff:0:0/96 35 4

Common Mistakes

• Disabling IPv6 on the wrong adapter: If you have multiple adapters (e.g., Ethernet and Wi-Fi), you might disable IPv6 on the one not in use. Always check the one with active internet.
• Using the wrong registry value: Entering the registry value in hexadecimal instead of decimal, or using a value other than 32, can have unintended effects. The value 0x20 (32 decimal) is specifically for preferring IPv4 over IPv6.
• Not restarting after registry changes: Registry changes often require a reboot to take effect. If you skip it, the system may still use IPv6.
• Assuming IPv6 is the problem: Sometimes the issue isn’t IPv6 itself but a faulty DNS or router. Disabling IPv6 won’t fix a broken DNS. Test with a different DNS like 8.8.8.8 before blaming IPv6.

Tips

• If you only have issues with certain websites, try using a browser that supports “Happy Eyeballs” (like Chrome or Firefox). These browsers automatically try IPv4 and IPv6 in parallel and pick the faster one, so you might not need to disable IPv6 globally.
• If you’re on a corporate or school network, check with your IT department before disabling IPv6. Some networks require it for certain services.
• After disabling IPv6, you can verify it’s off by visiting a site like test-ipv6.com in your browser. It will show that IPv6 is not available.
• To re-enable IPv6 later, simply go back to the adapter properties and re-check the IPv6 box, or delete the registry value you created.

Troubleshooting

No internet after disabling IPv6: This usually means your network actually relies on IPv6 (rare for home networks, but possible). Re-enable IPv6 by re-checking the box in adapter properties. If that doesn’t work, run ipconfig /release and ipconfig /renew in Command Prompt (Admin) to refresh your IP address.

Changes don’t seem to take effect: If you used the registry method and still see IPv6 traffic, double-check that you entered the value correctly and rebooted. Also, some VPN software or third-party firewalls can override these settings. Temporarily disable them to test.

Command Prompt says “Access denied”: You must run Command Prompt as Administrator. Right-click the Start button and choose the admin option.

Websites still load slowly: The issue might not be IPv6. Try flushing your DNS cache with ipconfig /flushdns and resetting your network stack with netsh winsock reset (then reboot).

Frequently Asked Questions

Q: Will disabling IPv6 break anything?
A: For most home users, no. IPv6 is not yet widely required for internet access. Some enterprise or specialized apps might rely on it, but for general browsing and streaming, you won’t notice a difference.

Q: How do I know if I’m currently using IPv6?
A: Visit a site like test-ipv6.com or run ipconfig in Command Prompt. If you see an IPv6 address (like 2001:db8::) assigned to your adapter, IPv6 is active.

Q: What’s the difference between disabling IPv6 and preferring IPv4?
A: Disabling IPv6 turns it off completely; Windows will only use IPv4. Preferring IPv4 means Windows still has IPv6 enabled but tries IPv4 first, using IPv6 only if IPv4 fails or is slower.

Q: I have a VPN. Will these changes affect it?
A: Possibly. Some VPNs route traffic over IPv6. If you have issues after making changes, disconnect the VPN, apply the setting, then reconnect. If problems persist, you may need to keep IPv6 enabled.

Q: Can I reverse these changes?
A: Yes. For the adapter method, re-check the IPv6 box. For the registry method, delete the DisabledComponents value or set it to 0. For the command prompt method, run the revert command mentioned in Step 4 of Method 3.

Q: Does this affect internet speed?
A: Not directly. If IPv6 was causing timeouts or packet loss, you’ll see an improvement. If IPv6 was working fine, you likely won’t notice any speed difference because most traffic is already over IPv4 anyway.

Related

• Windows Store Error 0x80072f05: Fix the Server Stumbled
• Windows PE: What It Is & How to Make a Rescue Disk
• Samsung TV Plus Not Working? Fixes That Work