The ‘Remove and Reinstall’ tool is the most efficient way you can fix Error 8504. You can follow the steps below to use the tool to fix the Norton error: • Step 1: Visit the website and download the Remove and Reinstall tool. • Step 2: Save the file on the desktop and close the browser. • Step 3: Click on the downloaded file and double-click the NRnR icon. • Step 4: Click Agree in the license agreement window and proceed. • Step 5: Go to the Advanced Options and click ‘Remove Only.’ • Step 6: Press ‘Remove’ again and then select the option to restart your system. Once the system restarts, you can call the norton customer care number and speak to a professional technician to learn how to reinstall the Norton product.