How to fix Norton antivirus Error 421?

How to fix Norton antivirus Error 421

Are you facing the Norton antivirus error 421? Nothing to worry about! Let us solve it by troubleshooting. The Norton antivirus error 421 is caused due to corrupted windows registry entries, incorrect installation of the Norton antivirus, malware attacks, etc. Let us see how to fix the Norton antivirus error 421.

Steps to fix the Norton antivirus Error 421

The Norton antivirus error 421 occurs while performing any work on your computer. Your PC might hang, or a runtime error might occur without any warning while your Norton antivirus is running in the background.

The following are some methods to troubleshoot the issue.

  • Step 1: Restart your PC
  • Step 2: In many cases, restarting your PC will provide you a solution for the error 421. First, close all the programs running in the background and try restarting your PC. Wait for a few seconds until the PC resumes and make sure that no error occurs while proceeding with your work.
  • Step 3: Close the conflicting programs
  • Step 4: At times, the Norton antivirus error 421 may be caused due to programs that are conflicting with each other. So, try to close the conflicting programs.
  • Step 5: Press the Ctrl, Alt, and Delete keys simultaneously to open the Task Manager window.
  • Step 6: This window will show you the list of programs that are currently running.
How to fix Norton antivirus Error 421?
  • Step 1: Close all the programs by selecting each program and clicking End now.
  • Step 2: If an error occurs while closing any program using End now, then select the Uninstall a program option.
  • Step 3: Identify the programs that are conflicting. You can find out the problematic program by checking if the error 421 pops up after ending each program.
  • Step 4: Uninstalling the conflicting program
  • Step 5: First, you need to go to the Start menu and click on the Control Panel option.
  • Step 6: Select Uninstall a program under Programs.
  • Step 7: Search and locate the program that conflicts and click Uninstall.
  • Step 8: Select Yes to confirm the uninstalling process and make sure that no error reoccurs.
Run the Norton Remove and Reinstall tool

Run the Norton Remove and Reinstall tool

In case none of the above steps help resolve the issue, then try uninstalling your Norton antivirus and reinstall the software. Uninstall your Norton antivirus from your PC and if the error still occurs, try the Norton removal tool to uninstall the program. Due to partial uninstalling, such errors might be caused, so uninstall completely using the Norton Remove and Reinstall tool.

  • Step 1: First, confirm that your computer is connected to the Internet and open your web browser.
  • Step 2: Go to the official web page of Norton to download the Norton Remove and reinstall tool.
  • Step 3: Download the latest version of the tool that supports your OS.
  • Step 4: Search and locate the NRnR icon from the Downloads folder and double-click on the icon to install.
How to fix Norton antivirus Error 421?
  • Step 5: Now, read and accept all of the Terms and Conditions and click Install.
  • Step 6: Wait for a few seconds until the installing process completes and click Advanced options on the Norton remove and reinstall tool page.
  • Step 7: Select Remove only on the remove or reinstall page and click Remove.
  • Step 8: Wait until the removal process completes and click Restart now.
  • Step 9: After your PC restarts, follow the on-screen instructions of the Norton remove and reinstall tool to reinstall the Norton antivirus software.
  • Step 10: The above methods should help fix the Norton antivirus error 421.