I don't think that even if you do "understand" (whatever that means) the application it gives you a license to load up a ton of software. I guess the question is how much is "a large number of realtime security". My observation is that over here 4-5 isn't considered large and many people run closer to 6-10 once you factor in privacy stuff or if you desire backuping just in case. In fact if I look at the answers you give Blue, it seems at least 4 is necessary. Most likely 5 if you run two for the last entry. And all this is on top of a hardware router. 1. AV 2. AT with good memory scanner 3. Firewall 4. Process/file/registry guard/monitor/protection And for some people, this might even understate matters since some of the entries 1-4 overlap with others. People trying to run KAV 6 full on with online armor, appdefend . Then again there are people who are minimists running around trying to prove they can surivive only with shadowuser. Oh well.