I have a repeating popup telling me my computer is infected. Guardio blocks says it brlocked it but it continues to pop up. Even after I just installed Firefox.

Hi there. I keep getting a pop up that says my computer is infected, etc. It pretends to be windows with several buttons to cure the problem... When I to into security settings windows says it blocked it and gives me the correct time that it was blocked. It keeps popping up even with the Firefox browser. When I watch a movie it does not pop up....??? Movie on u-tube. Thank you for any thoughts. Ok , here it is again.. In a different form..."Your Norton has Expired. " It has a button for "Enable protection" and a protect and close button. The address is d6megpo029pc73bd7vt0.visolabala.co.in I was unaware that I have Norton protection. It offers it at 29.99 per year. It has a "protect" or "close" button under that. I normally click of the faint "X" in the middle of the right of the page. If it is Norton, I would like to sue them for infecting my computer. But I don't think it is Norton. thanks again for your thoughts. CH