I am currently trying to install Kaspersky Total Security, but it persistently asks me to uninstall all other antivirus software: McAfee Security Scan Plus and Avast Software(Free). They claim their software won't work well if other antivirus programs are installed.

I can understand that two simultaneously working antivirus software could conflict with each other, but would they conflict if I turn the other antivirus software off before launching Kaspersky? Or is it just a marketing trick from Kaspersky lab?

2 Answers 2


"Is it necessary or is it a way to be forced to only use the one product?"

It depends. There are many, many cases where overlapping AV fight with each other and cases where certain products work well together. As products evolve and add new methods of detection, it becomes increasingly difficult to predict the effects of interaction.

I'm not sure what the marketing advantage is to have a monopoly on the desktop when the customer has already acquired a competitor. So, I'm not sure that is a motivating factor.

However, from a troubleshooting and support perspective, it makes sense for a vendor to side-step the complexity and say to only use one.

  • 1
    In addition, it can also eat up a lot of resource having multiple antivirus software: lifehacker.com/… Commented Jan 30, 2020 at 10:35
  • @AlexProbert sure, and there are other effects, but in terms of "necessity" the issue is not being resource intensive.
    – schroeder
    Commented Jan 30, 2020 at 10:38
  • How can a completely turned off AV with all its processes shut down affect another AV methods of detection?
    – narra_kk
    Commented Jan 30, 2020 at 11:31
  • @narra_kk because "completely shut off" might not mean "completely". There might be protected, replaced, or encrypted parts of the system that the one AV manages that the new one might not be able to access. The point is that AV burrows deep into the operating system and you might not know all it does to know if it is off or not active.
    – schroeder
    Commented Jan 30, 2020 at 11:34
  • And as my answer explains, it might be fine, but there is no way to know beforehand.
    – schroeder
    Commented Jan 30, 2020 at 11:35

Viruses manipulate the way the operating system communicates with its components, so the antivirus must necessarily act in advance by blocking the attempt. If this means installing system components that act at the kernel level, a previously installed antivirus could identify the attempted manipulation as malicious, even if the software is actually used to avoid such activity. It is for this reason that the only software that can keep the system under control at the kernel level must be the antivirus and must be unique.

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