How to troubleshoot Norton Error 8505 and 129?

Recently, I encountered a couple of error codes due to the fact that I was trying to update my Norton setup, and found that the device barely had enough space to get the updates installed. Tricky, isn’t it? Now, you have to compromise some of your data to vacant memory storage necessary for the updates.

Fortunately, there are countless cleaning applications, and trash file removers available online for free that can help you get copied content, junk files, duplicate files, and unwanted applications removed from your device. However, that might not be enough to resolve the issue. Under these circumstances, you may receive the error codes 8505, 129.


The primary cause for the emergence of 8505 and 129 error codes can be excessive storage of unwanted programs. To get this error fixed in no time, you can try rebooting your device. If this doesn’t help, then you might need to check your Network proxy Settings and run a full scan on your device to get rid of useless applications that you neither want nor you ever downloaded with Norton Power Eraser. You can download the Norton Power Eraser via

Step 1: Go through the steps to ensure Network Proxy Settings are configured as required

  1. Click on Window + R tabs to pop-up the Run Dialog Box
  2. Now, type cpl and then hit the enter button to launch the Internet Properties on your device
  3. Go to the “Local Area Network” Settings from the “Connection” tab
  4. Once the LAN settings dialog box open, go underneath the “Proxy Server” option and make sure that all the check boxes are not selected
  5. If you find any entries under the Proxy Server, uncheck the boxes and opt for “Automatically detect settings”

(If there is unidentified Proxy address visible on the screen, then it probably means there is some potential threat or unwanted application exists. You’re recommended to execute an Advanced scan on your device with Norton Power Eraser)

  1. Press “OK”
  2. Press “Apply” and then click “OK”

If the error codes are yet to be resolved, proceed with steps 2

Step 2: Run the Norton Power Eraser

  1. Open your web browser and go to
  2. Sign in your Norton account and download the Norton Power Eraser tool
  3. Once the NPE.exe file is downloaded, save it on your desktop
  4. Make sure to select desktop as the destination to save NPE.exe file and hit the “Save” button
  5. Go to the desktop and click twice on NPE.exe file to initiate the execution process

(If the “User Account Control” window prompts, click “yes” or “Continue”)

  1. Review the end user license agreement carefully and click on “I Agree”
  2. From the Norton Power Eraser wizard, tap on “Unwanted Application Scan” symbol

(Once Norton Power Eraser completes the scan, the outcomes will be visible in the “Unwanted Apps Scan Complete” Window)

  1. In the “Unwanted Apps Scan Complete” Window, next to the unwanted application or toolbar, press “Uninstall”
  2. Proceed to the next step and follow the rest of the guidelines displayed on the screen
  3. Restart the system after the installation is complete


If the issue still continues to bother you, go to the unwanted toolbars that display all the non-essential programs installed on your device. For more information on removing such files, you can contact Norton Setup Customer Support for technical support.

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