I have come to use Computer Associates for virus protection - I find their software to be pretty transparent in terms of pop-ups, updates, etc. Set it and forget it. Other virus protection (MacAfee and Symantec) seems to be in your face a bit too much, slows things down, uses up resources.
Except, when the recent "your virus software is about to expire" pop-up came through and I re-licensed it for my laptop, the license code they sent did not work. I uninstalled the software, reinstalled it. Just sent message #2 to tech support (message #1 went unanswered other than an initial acknowledgement)
So now I have no (or compromised) virus protection. Grumble.