It’s almost as bad as not having one at all.
You might think that, when trying to protect your computer, doubling up on antivirus programs is the safest measure. However, it turns out that that isn’t actually true. Here are a few reasons why:
They won’t recognize each other as safe programs
“Antivirus programs do not usually play well together, and running two at the same time will often lead to one singling out the other as a virus, or in some cases, even cause file corruption,” according to a LifeHacker article.
The reason for this is that antivirus programs look for suspicious activity such as programs that are monitoring and sending information about your system. Since that is precisely what antivirus programs do, program A might see program B as a virus and thus detect a problem that doesn’t really exist.
They will fight over viruses
As an antivirus program detects suspicious files, it quarantines them to keep your computer safe. If you have two programs running at the same time, program A may start detecting files that program B has quarantined and try to move them elsewhere. Then, in turn, program B may re-detect these files and you could end up with both programs running in a vicious circle.
They will use up your battery life
Antivirus programs run in the background on your system. They don’t use up much battery power on their own, but when you combine two, that start to eat into your computer’s battery life — especially if they are needlessly fighting each other.
If this all still seems counterintuitive to you, I will leave you with PC World’s take on the matter: “Running two antivirus programs simultaneously is a bit like mixing a fine, vintage Cabernet with breakfast cereal. Each is good on its own right, but the combination may have unpleasant effects.”
If you really feel like you need more than one antivirus program, consider having one running in the background all the time and having a second one that you turn on periodically — after turning off the first one of course.
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