Norton 360 not found

I could not see the usual icon in the active icons so I tried opening from the start menu. Nothing would open it. I did a search and it said the program was not on my computer. Where in the world would it have gone? I have been using 360 since 2010. I tried re-downloading after undoing one of my 3 codes. I have only gotten error messages and cannot download it. Do I have a setting somewhere keeping me from being able to do this simple function? This is getting to the point of being frustrating. Any assistance is greatly appreciated.