Until today I used for a long time G Data, F-Secure and ZoneAlarm, and I've never had a problem with threats, have always used them alone because arrested for performance, I've never needed to use these helper programs as many use, because it is not necessary, it only swells the system and makes you more paranoid yet, in my opinion is completely unnecessary to install 4, 5 security programs to "protect" a threat that will never come (mainly for common user), security suites with the mentioned above already are more than enough to protect you