The vast majority exist as adverts for their bigger siblings, as companies do their best to sell you upgraded versions with more features and 'enhanced' protection.
These things need to be running all the time, and if they're annoying or hit your system resources too hard you'll have them uninstalled in a flash.
Smart and well designed, with excellent detection rates, Avira is our pick of the bunch
Yes, AV-TEST's results show it to have a micron less protection than the likes of AVG, but it's the slickest, cleanest and least system intensive antivirus package going.
It's almost as if the programmers sat down to determine exactly what users would want out of an antivirus package and somehow stumbled on the correct answer: something that isn't in your face every two seconds and doesn't slow your PC to a halt just by existing.
It's not the glossiest package, and the install process is a bit pre-emptive, with Windows 10 repeatedly shouting at us to update Avira before it had even finished making its way onto our test machine, but we're inclined to blame Microsoft for the latter glitch.