How to Reinstall Norton 360
If Norton 360 was previously installed on your computer or has become corrupt, you may need to reinstall the software. The Norton installation software removes early traces of the software when it installs a new version, so Symantec (Norton's developers) suggest downloading the latest version of their software to begin the installation. You may need to re-enter your serial number during installation.
Navigate to the Norton 360 download page.
Download the most recent version of Norton 360.
Double-click the set-up file.
Complete the onscreen instructions to reinstall Norton 360. Enter your serial number if prompted.
Click "Finish" at the end of set up.