@Julie777 Whether we use Software Updater or not Norton still runs it in the background. I DO NOT use it and have my settings as shown below. Set yours the same, restart the computer, recheck. Lets us know if things change for you. We on the forums suggest EXTREME CAUTION using SU as it can render a computer not usable in some instances.
Turn Auto-Update OFF
Next open the Settings tab and disable these three settings
SA