Based on the smarts of the folks around here, I suppose this forum is as good as any for this question. Plus it goes to the matter of Prevx saying it will work fine side by side other AV/AT/AS/AM. Why is it ok to run multiple security apps with realtime scanners? What I get: Layering is wise from the standpoint you are not trusting your security to any one vendor or methodology. You can set exclusions for Product A in the settings of Product B, and vice versa. A security app compnay stands to sell more licenses saying, 'You can add our stuff without having to make the huge decision to drop someone elses stuff.' What I don't get: The dinner table food fight analogy. You have a plate of meatloaf on the dinner table (malware.) Bobby (security app A) sees it and grabs for the plate. Sally (security app B) also see the meatloaf and grabs for the plate at the same time. Mom (computer user) can tell Bobby and Sally to ignore each other (exclusions lists.) And while Bobby and Sally may be ignoring each other, you still have both of them grabbing the plate. If one of them doesnt say "uncle" what is going to happen to the plate of meatloaf? And if this goes on long enough while mom is away from the table (User away from the PC) there surely is a risk of the PC locking up, BSOD, etc. Who ultimately handles the meatloaf in the end? And if there is a BSOD, you may not have gotten infected, but you may have just corrupted or lost valuable data that was active during that Windows session. Corrupted and lost data is just as bad as having gotten infected. As you can tell from the analogy, security software guru I am not. I'm sure I am missing some basic concepts here. Ive recently come to fully grasp no one security app can protect you from everything. Running multiple apps to cover bases and patch holes is my natural inclination. And trusting one app leaves me feeling truly hesitant. But the analogy above does make me wonder if Microsoft might have a valid point when saying - you should not run more than one app with a real time scanner. If security vendors can start to grasp that, to the end user, corrupted data is equally as bad as infected data, If two apps try to grab, quarantine, react to the same piece of malware at the same time, If each security app is set to ignore the other, yet they both try to respond to a piece of malware, Why would it be ok to run multiple real time apps? conundrum.