Anti-Virus Solution

Norton Autofix identified an issue: Fix Norton 360 Installation has encountered an error 8404 on Windows


Norton 360 is a comprehensive cybersecurity and antivirus software suite developed by Norton LifeLock. It offers a range of features to protect your PC and personal data from various online threats, including viruses, malware, ransomware, and phishing attacks. In this article, we shall discuss how to fix Norton 360 Installation has encountered an error 8404 on Windows. Please see How to set up Norton Cloud Backup on Windows, how to Can’t connect via RDP upon installing Norton 360, and how to Download and install Norton 360 Anti-Virus on your Mac device.

Most times, this error might be due to some common inconsistency caused by some transient files that interfere with the updating operation. You should start with a temporary solution by restarting your PC to see if the problem persists. If it does persist, please follow the steps below to resolve the issue.

Why was the error prompted?

The following error is prompted when you launch Norton 360 on Windows when you try to launch the Norton Security Application.

Norton 360 Installation has encountered an error on Windows

After the first try, when you try to launch the Norton 360 application again. The following error below is prompted.

Norton Auto Fix

This is where Norton AutoFix Tool becomes useful! This tool is used to get rid of Norton errors. The tool quickly detects an error and then fixes it. But in my case, it failed and did not resolve this issue!

But, as you can see, Norton Autofix failed to resolve this issue as mentioned above. Upon clicking on fix it, the following window below will be prompted and we can see the LiveUpdate and installation also failed via the AutoFix.


Resolve “Norton 360 Installation has encountered an error on Windows”

To fix this issue, you will have to uninstall and reinstall Norton. To do this, download and run the Norton Remove and Reinstall tool to uninstall and reinstall Norton.

Download the Norton Removal File and Reinstall Tool

Download and run the Norton Remove and Reinstall tool. Open the Downloads window and locate the NRnR file as shown below.

Run the dowwnloaded NRnR tool

Read the license agreement, and click Agree.


Click Remove & Reinstall.

Remove & Reinstall

Click Continue Download Norton.

Remove and reinstall tool running

Norton 360 is being downloaded

Downloading Norton

Shortly, you will see the application (Norton is being uninstalled)


When prompted, click Restart Now.

Windows PC restart due to Norton issues

You may want to see how to Enable or disable Norton silent mode on Mac and how To Get Install.WIM From Windows 10 Installation File. Also, see how to fix repeated app-blocking connection alerts from Norton on Mac.

Reinstall Norton 360

After the computer restarts, follow the on-screen instructions to reinstall Norton.

Note: This might take a while to luanch, please wait for it to start.

Accept the license and click on Install

Reinstall Norton

The installation will continue as shown below.

Norton is running

Configuring Norton Components

Configuring Norton Components

Updating Virtus definitions

Updating Virtus definitions

The Norton Antivirus Server will be contacted very shortly. The product will be activated

Contacting Norton Server
Sortly, you will be prompted to sign in. 

Please enter your email and password.

Sign into Norton

If you have the MFA setup which is necessary to protect your Norton account. Kindly enter the 6-digit code in the box below.

Norton 2FA

Wish to interact more, you can open the Norton “Device Security” and perform any of the operations.

Norton Application

You can also interact with your Norton Security Solution via the classic Device Security as shown below.

Device Security

FAQs relating to Norton 360 Installation have encountered an error 8404 Error

What should I do if I cannot resolve the error on my own?

If you have followed the steps above and are unable to resolve the error. I would recommend you contact Norton Support for further assistance. They can provide more specific guidance and solutions based on your system’s configuration and the exact cause of the error.

Why am I encountering error 8404 during Norton 360 installation?

There can be various reasons for this error, including conflicts with other security software, incomplete installation or uninstallation of previous Norton products, corrupted installation files, or issues with your Windows operating system.

I hope you found this blog post helpful on how to Fix Norton 360 Installation has encountered an error 8404 on Windows. Please let me know in the comment section if you have any questions.

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