Get rid of McAfee popup ad

How do I avoid the nuisance of this popup ad for antivirus?

McAfee gave up after two days. The popup has not shown up so I can't take the screen shot. 

Thanks for the answer, though; I'll know better next time.

John Viser

McAfee gave up after two days. The popup has not shown up so I can't take the screen shot. 

Thanks for the answer, though; I'll know better next time.

John Viser