Step 1. Modify TCPIPv6 Parameters through Windows Registry.

1. Open Windows Registry Editor. To do that:

   • Press “Windows” + “R” keys to load the Run dialog box.
   • Type “regedit” and press Enter.

     IMPORTANT: Before you continue to modify the registry, first take a registry backup. To do that:

     • a. From the main menu, go to File & select Export.
     • b. Specify a destination location (e.g. your Desktop), give a filename (e.g. “RegistryBackup”) and press Save.
2. Inside Windows Registry, navigate (from the left pane) and highlight this key.

   HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\TCPIP6\Parameters

3. At the right pane, double-click to modify the DisabledComponents key.
4. Set the DisabledComponents Value data to 0 (Zero) and select OK.
5. Close Registry Editor.
6. Restart your computer. (Windows should reinstall Teredo Tunneling adapter automatically.)
7. Navigate to device management.

8. Check if the Teredo tunneling adapter exists and working in device manager. To do that:

   • From the View menu choose Show hidden devices.
   • If the device manager’s screen doesn’t show any errors (and is without an exclamation mark) next to MS Teredo Tunneling Adapter (like the screen below), then your problem is solved and the Teredo tunneling should work without problems.
   • If you face a screen with a yellow exclamation mark next to Microsoft Teredo Tunneling adapter (or the Teredo Tunneling Pseudo Interface) like the screen(s) below continue to Step 2.

Step 2: Uninstall all Teredo Tunneling Adapters & Interfaces.

1. Right-Click and Uninstall the Teredo Tunneling Pseudo-Interface.
2. Uninstall also all Microsoft Teredo Tunneling Adapters (e.g. Microsoft Teredo Tunneling Adapter #2 or #3 or #4, etc.)
3. Re-install Microsoft Teredo Tunneling Adapter by following the steps from this tutorial: How to install Microsoft Teredo Tunneling Adapter
4. If after re-installing teredo tunneling, you still have problems then proceed to Step 3.

Step 3. Enable Teredo Client using NETSH command

1. Go to Start > All Programs > Accessories.
2. Right click at Command Prompt and select Run as Administrator
3. At command prompt window type the following commands in this order and press Enter after typing each one of them.
   • netsh
   • int teredo
   • set state disabled
   • int ipv6
   • set teredo client
4. Close command prompt.
5. Open Device manager.
6. Select View > Show Hidden Devices. The Teredo Tunneling Pseudo Interface reappears and should be working without problems now.