Is this a scam?

I don't have Norton Security installed on my computer. Sometimes I'd get these very sudden, very abrupt pop-up of Norton Security telling me I have a virus and doing an actual virus scan. Then another pop-up appears saying I have to upgrade Norton Security. Now I thoroughly check to confirm if I have any viruses, and everything comes up positive. So why does this pop-up of Norton Security happen? I don't have it installed, so why does it randomly appear as if I did have it installed?
Answers

Gary

Yup

rick29148

many of those 'pop-ups' are triggered by cookies buried somewhere on your HDD; give your box a good cleaning & see if that helps ..................

Alexa

Yed

Twila

norton is a scam in itself; just ignore those ads