How to Fix Norton 360 Error 8506 and 421 for Windows 7?

Norton-360 Error 8506 and 421 message generally appears during installation of a program. Though most of the times, this 8506 and 421 error problems can be resolved by restarting your system, but sometimes even after restarting, this issue persists. In that case, you need to reinstall or uninstall your Norton product from your system. When a Symantec related software program is processing during program installation or during Windows startup and shutdown or during the installation of the Windows Operations system, This Norton 8506 and 421 error occurs in Windows 7 system. To Fix Norton 360 Error 8506 and 421 for Windows 7, it’s crucial to keep track of when and where that error occurs. Norton 360 Error 8506 and 421 can harm your system is several ways if not fixed in time. This error can occur due to many reasons, such as:

  • Unfinished installation of an application
  • Corrupt download of Norton Internet Security
  • Malware or Viruses infecting Norton security related files or Windows Files
  • Wrong or harmful deletion of Norton-360 internet security related files

Moreover, below is a list of troubleshooting steps to resolve this issue. The process can be a bit difficult and time consuming if not followed proper steps.

Norton 360 Error 8506 and 421 for Windows 7










Steps to Fix Norton 360 Error 8506 and 421 for Windows 7

Below are the steps to troubleshoot Norton 360 Error 8506 and 421 explained by our Norton Security expert team.

Fellow this process to prevent the error in time.

Step1: Fixing of registry entries associated with the Error 8506-421

  • If you are not a PC service professional, it is advisable that never try editing manually the Windows Registry. One wrong editing may lead to reversible damage to your Operating System. A single comma can make your PC from booting completely.
  • Due to the higher risk, our Norton tech support team highly recommends to use registry cleaner tools like WinThruster to scan and fix any registry related problems. A registry cleaner tool automatically finds invalid registry entries, missing files and broken links while creating a backup. It prevents your PC from possible damages while improving system speed and performances.
  • To repair manually Windows registry, first thing you need to do is to create a backup of the portion related to the error. Then follow the following process:
    • Click on the “START” button
    • Type “COMMAND” in the Search Box. DO NOT hit ENTER immediately.
    • Hold “CTRL+SHIFT” on the Keyboard and then HIT “ENTER”.
    • Click YES on the Permission Dialog Box.
    • Type “REGEDIT” on the black screen that opens followed by “ENTER”.
    • Select the portion from the registry editor, you want to back up.
    • Choose “EXPORT” from the “FILE” menu.
    • Select the folder from the “SAVE IN” where you want to save the Norton 360 backup Key.
    • Save the File with a File Name such as “Norton 360 backup”
    • Select the “SELECTED BRANCH” in the “EXPORT RANGE” Box.
    • Click SAVE to save the file in .REG FILE EXTENSION.
    • You now have the backup of the Norton 360 related registry entry.

It is better not to try manually editing your registry because of the high of damaging in your system.

Step2: Make a full Malware scan of your PC

There are possibilities that a Malware infection on your PC is behind the 8506 and 421 error. Those harmful intruders can damage or corrupt your system in the long run. Use EMSISOFT ANTI MALWARE to remove the Malware or viruses from your system successfully.

Step3:  Remove Junk Files like Temporary files and Folders with Disk Cleanup

It is normal for every PC to accumulate Junk Files due to web surfing and Computer use. If those files are not cleaned up, it can overload your hard drive or cause a conflict which will make Norton 360 to respond slowly. Cleaning junk files will not only boost your PC’s performance but also solve your 8506 and 4214 error. Use WinSweeper, a privacy protection software to clean your computer. Using of WinSweeper once a day will prevent your system from junks, bugs and 8506 and 421 errors.

How to process disk Cleanup?

  1. Click on START button.
  2. Type “COMMAND” in the Search Box. DO NOT hit ENTER immediately.
  3. Hold “CTRL+SHIFT” on the Keyboard and then HIT “ENTER”.
  4. Click YES on the Permission Dialog Box.
  5. Type “CLEANMGR” on the black screen that opens followed by “ENTER”.
  6. Then “DISK CLEANUP” will calculate the space occupied by junk files.
  7. Select the boxes from the category you want to delete and then click “OK”.

Step4: Update the Drivers of your system

Updating outdated and corrupt drivers can help in preventing Norton 360 8506 and 421 error from occurring.  Drive update tools like DriverDoc updates your PC’s drivers creating a backup. Maintain drivers can also be a reason to fix Norton 360 error 8506 and 421 for Windows 7.

Step5: Use Windows System Restore to UNDO recent changes

Windows System Restore helps you by returning back to the time when your PC was working fine.  To use this facility:

  1. Click on “START” button.
  2. Type “SYSTEM RESTORE” in search box and press “ENTER”.
  3. Click “SYSTEM RESTORE” in the result by entering any administrator password.
  4. Click on “WIZARD” to choose a restore point.
  5. Restore you computer.

Step6: Download Norton 360 Remove and Reinstall tools.

The best way to prevent your system from Norton 360 8506 and 421 error is by downloading Norton 360 Remove and Reinstall tools.

Related Blog Understanding and Troubleshooting Common Errors of Norton Antivirus

  1. Save the file in your desired location.
  2. Later on open downloads window in your browser and double click on the NRnR symbol to run.
  3. Click on “AGREE” on the license agreement.
  4. Thus click on Advanced Options to select REMOVE only.
  5. Finally click on “REMOVE” and “RESTART” followed by the instruction to reinstall Norton product.

Dial Norton Customer Support Number For Immediate Help






Dial up our Norton Customer Care Support Phone Number to contact with a team of dedicated and professional experts. They will help you in resolving your any kind of Norton 360 product related issues with sound knowledge and efficiency.  Their easy assistance will resolve your Norton antivirus technical issues in no time. Hence, make a call to Norton Support Number to avail the customer satisfactory facilities now.