How to Run Two Antivirus at the Same Time and Not Have Problems

Run Two Antivirus at the Same Time

A good antivirus is essential to be able to connect to the Internet safely and not take unnecessary risks. This software is responsible for analyzing all the files that reach our PC, as well as auditing the connections and blocking everything that may seem dangerous. Good security software is more than enough. However, there are some users who think that two is better than one. And, although this phrase may be true in many contexts, when we talk about antivirus it is not. And not only that, but we can even have a lot of problems if we don’t do it right.

Threats are becoming more complex, and we cannot entrust all our security to a single program . It is also necessary to follow a series of basic tips to be able to be safe online. For example, we must avoid clicking on the links that we see on social networks, or download files from suspicious websites or that reach us through email. Updating Windows, and the PC programs, is also vital to prevent cyber attacks. And everything we download, even if it seems safe, must go through an antivirus.

Dos antivirus PC

Problems of using two security programs at the same time

Why if one antivirus works, two don’t? The reason for this is at a very low level, to the way these programs work. Antiviruses are critical programs for the system. For this reason, this type of software is the little that is installed with SYSTEM permissions , the highest level of Windows privileges. Thanks to this, you have control over everything that happens in your system, and you can detect and block threats no matter how persistent they are.

When trying to install a second antivirus, it tries to install anyway with SYSTEM permissions. By already having software installed with these permissions, and detecting this action, it will detect it as dangerous , since nothing should be installed with those permissions. Therefore, the first problems that we will encounter are when installing it.

In case the second antivirus is installed , the problems will begin as soon as the protection shields are tried to be activated. If the security software only has detection based on a database, in addition to being useless, it will not cause problems. But if it works with heuristic functions that analyze behavior, it will run into the engine of the other security software installed on the PC, and therefore it will literally start to fight with it.

It can also happen that the two antivirus engines installed on the PC try to access the same file at the same time. Neither of them would manage to take possession of it, which would skyrocket CPU consumption and end in an error.

Finally, it is necessary to emphasize that, if we manage to avoid all these problems, we would have another one: performance. Any antivirus program is constantly running on the PC, analyzing all activity. And that translates into a more than considerable CPU and RAM expense . If we have two security programs on the PC, the use of resources will skyrocket, and the whole PC will go slow.

How to run two antivirus at the same time

Although we can run into a lot of trouble trying to get this to work, it’s actually not impossible. You just have to know how to do it, and choose the right security programs.

Use Windows Defender

If we have already installed an antivirus on our computer, whatever it is (Avira, Kaspersky, Norton, McAfee, etc), we will already have a second security program on the PC: Windows Defender.

Windows Defender - Ventana principal

When we do not have another security program, the Windows antivirus is the one that takes care of all the security. However, when you install a second security software, it is automatically disabled, leaving it only for manual background scanning. In this way, this antivirus does not alter the operation of our main security program, and it serves us perfectly to obtain a second opinion in case we do not fully trust our security program.

Malwarebytes, the quintessential “second antivirus”

The important thing is that, when we are going to install a second security program on our PC, it is that it is not constantly analyzing the computer, but rather that it allows manual analysis. One of the best known, and the best option we can choose for this purpose, is Malwarebytes . This is not an antivirus as such, but it is an anti-malware specialized in other types of threats to the PC, threats that, generally, can go unnoticed among other security programs.

Interfaz principal Malwarebytes Premium

Malwarebytes is a security program specialized in detecting threats , other than typical viruses and Trojans, on demand. That is to say, it is a security software that has been designed from scratch to be able to work without problem together with other security programs. This software has never been a problem to install on a computer with Windows Defender, Kaspersky, Norton or any other security program. Therefore, it is one of the best options we have to be able to have a second opinion of the security of our PC.

Of course, we must be careful if we choose to install the “Premium” edition of this program. By default, it will be registered within the Windows security center, and it will deactivate any other antivirus installed on the PC. If we want to use Malwarebytes as a second antivirus, it is better to opt for the Free edition. Or, at least, deactivate the registration option in this security center, within the Settings> Anti-malware security options.

If we use the Premium edition, we can also make this anti-malware run in real time on the PC, together with another antivirus. Of course, we must make sure to add a series of exceptions in our main antivirus software so that it does not conflict with it. These exceptions are:

  • C: Program FilesMalwarebytes
  • C: ProgramDataMalwarebytes
  • C: WindowsSystem32driversmwac.sys
  • C: WindowsSystem32driversmbamswissarmy.sys
  • C: WindowsSystem32driversmbamchameleon.sys
  • C: WindowsSystem32driversfarflt.sys
  • C: WindowsSystem32driversmbae64.sys (64-bit)
  • C: WindowsSystem32driversmbae.sys (32-bit)

Portable antivirus

As we have explained, most of the problems come when it comes to installing the security program and configuring the background scans. Therefore, if we use alternatives that do not have to be installed, and that do not monitor our PC in real time, there is no problem.

Portable antivirus are versions of these designed to run from a USB without the need to install anything. In addition, you disable real-time analysis, and many other functions, to avoid conflicts with others. We can run any portable antivirus, regardless of the program that we have installed resident in the computer, to obtain second opinions about the security of the computer and be sure that no threat is hidden on the PC.


The problem with this type of program is that, except for a specific one, such as ClamWin , most are modified versions of the originals. And that always means taking unnecessary risks.

Do I need to install a second antivirus?

Today, practically all antivirus share databases thanks to the cloud . And one example of this is that in the independent tests of AV-Test and AV-Comparatives, almost all obtain the same results. However, there are threats (beyond viruses) that some detect better than others.

If we want to be really sure that nothing is hidden on our PC, the best we can do is install a good main antivirus , one that has a good rating. Windows Defender, for example, if we want a free one, or a security suite such as Kaspersky, McAfee, Norton or Bitdefender if what we are looking for is a more complete comprehensive solution. And, for the second opinion, a Malwarebytes will be more than enough.