After doing that, check if the problem is resolved.
3. Make sure IP Helper is running
- Press Windows Key + R and enter services.msc. Now press Enter or click OK.
- When Services window opens, locate IP Helper service and double-click it to open its properties.
- Set Startup type to Automatic and then click Start button to start the service. Click Apply and OK to save changes.
In order to use Teredo, you need to have the IP Helper service running. If this service is disabled for some reason, you’ll encounter Teredo is unable to qualify error.
However, you can fix the issue by using this solution, with the steps shown above.
Once you start IP Helper service, the problem with Teredo should be resolved completely.
Several users reported that IP Helper service won’t start due to issues with dependent services. However, you can solve this problem by doing the following:
- Open Services window and double-click IP Helper to open its properties.
- When Properties window opens, navigate to the Dependencies tab.
- Now look in This service depends on the following system components section.
- Expand the list and write down all the services.
- In most cases the problem is WinHTTP Web Proxy Auto-Discovery Service, so be sure to check this service first.
- Now go back to the Services window and make sure that these services are running. If not, enable them.
- After doing that, try to start IP Helper service again.
If the IP Helper is already running on your PC but you still have the problem, simply restart it and check if that fixes the issue.
Several users reported that restarting both IP Helper and WinHTTP Web Proxy services was a good starting step.
After that, running a command was the second step that fixed the issue for them. Try out this simple two-step solution and type in the following:
netsh interface teredo set state type=enterpriseclient
4. Reinstall Teredo
- Press Windows Key + X to open Win + X menu. Select Command Prompt (Admin) or Powershell (Admin).
- Now run the following command:
netsh interface Teredo set state disable
According to users, sometimes in order to fix the Teredo is unable to qualify message you need to reinstall Teredo completely.
This requires you to stop the Teredo service and remove the Teredo driver. This is quite simple to do, and you can do it by following the steps shown above.
After disabling the Teredo service, you need to remove its driver by doing the following:
- Open Win + X menu and choose Device Manager from the list.
- When Device Manager opens, go to View and select Show hidden devices from the menu.
- Locate Teredo in the Network Adapters section, right-click it and choose Uninstall device. Repeat this for all Teredo devices.
- Uninstall anything you see with Teredo in it from the right-click menu
- Restart your PC and re-enable Teredo with this line in Command Prompt (Admin):
netsh interface Teredo set state type=default
- Make sure to NOT manually install the Teredo Tunneling Pseudo-Interface adapter as it might cause trouble since it reinstalls automatically
Alternatively, you can use specialized removal software that will take of this procedure for you.
In fact, software tends to leave traces behind and generate clutter that will eventually take its toll on your disk space, so you might want to make sure you properly uninstalled Teredo in the first place.
We recommend you Iobit Uninstaller, an excellent tool to remove unwanted software with only a click. It works great even when you want to remove bundled software.
Containing an enlarged database, Iobit Uninstaller allows you to remove 30% more residual files and 5x problematic software. Protect your privacy with this tool by removing malicious plugins and toolbars too.
The Iobit Uninstaller is also great when you want to browse in a smoother online environment. You can use its Browser Notification Block to turn off annoying pop-up notifications.
This performant program does more than just uninstall programs as it also removes the remaining files. More, Iobit Uninstaller has a reminder feature that notifies you about all available updates for your software.
5. Check for an invalid value on the Teredo server name
- Default correct parameter in Windows 10: win10.ipv6.microsoft.com.
- Check for the correct parameter with the Command Prompt line
netsh interface Teredo show state
- If the parameters aren’t correct, use this command line to revert them:
netsh interface Teredo set state servername=default
If you keep getting Teredo is unable to qualify error, you might be able to fix the problem simply by checking the server name value.
This is quite simple, and you can do it from Command Prompt just with the commands and parameters from this solution.
After making these changes, check if the problem with Teredo is resolved.
6. Make sure the host file entry isn’t causing problems
- You can check this with the command line
netsh interface Teredo show state
- If it displays the message failed to resolve server name, use the command line
- Use Notepad’s Edit/Find function to search for win10.ipv6.microsoft.com and use the Find Next feature until you find another entry which you will subsequently delete.
According to users, sometimes this problem can appear if the hosts file is changed. You can check your hosts file by following these simple three steps.
Many users reported Access denied message when editing hosts files, and this is just a security warning.
We explained in one of our earlier articles how to circumvent this problem, so be sure to check it out.
7. Re-enable IPv6 on all tunnel interfaces
- Navigate to this Microsoft’s support page.
- Now locate Re-enable IPv6 on all tunnel interfaces and click Download.
- Once you download the file, run it, and check if that solves the issue.
If you’re having problems with Teredo is unable to qualify message, the issue might be related to IPv6. Sometimes IPv6 can become disabled on tunnel interfaces and that can lead to these problems.
To fix the issue, you need to download a file from Microsoft that will re-enable all IPv6 interfaces. This is quite simple, and you just need to follow the previously shown steps.
8. Create a new user account
- Press Windows Key + I to open the Settings app.
- When the Settings app opens, navigate to the Accounts section.
- In the left pane, navigate to Family & other people.
- In the right pane, click Add someone else on this PC.
- Choose I don’t have this person’s sign-in information.
- Select Add a user without a Microsoft account.
- Enter the desired user name and click Next.
Sometimes you might be able to fix the problem simply by creating a new user account. This is rather simple just like in this solution.
After creating a new account, switch to it and check if that solves your problem.
If the issue is resolved, you might want to consider moving your personal files to the new account and using the new account instead of your old one.
Teredo is unable to qualify message can cause issues on your PC, but we hope you managed to solve it using one of our solutions.
This post was written by Radu Tyrsina and was first posted to WindowsReport