Viruses are scary. Other kinds of malware are scary too. These things can not only destroy your computer, they can also steal your money and your identity and mess up your life in quite a serious way. Naturally, as a computer user who spends a lot of time online (and who doesn’t, these days?) you want to be as protected as you can be. So what do you do? You get an antivirus program. But you still don’t feel safe enough, so you get another one. Some people have five or more different antivirus programs, all from different brands, or from the same one, but in different versions. The more the merrier, right? It can’t hurt to have a little extra solders in the trenches, right? Wrong and wrong!
Every antivirus manufacturer will tell you that it is never a good idea to have more than one antivirus program installed on your computer. You might think that this is because they fear the competition and they want you to use their product only, but that’s actually not the reason why having more than one AV program is a bad idea.
It’s more of a technical issue. Consider how an antivirus program works from a strictly laymen point of view. It has high authorizations on your computer and it digs deep into its heart to search for potential trouble. It’s really deep down in there and it’s eating up a lot of your computer’s resources. Most antivirus programs cause at least a little bit of system impact and slow things down. Now imagine having more than just one. Imagine how hard your computer would have it with two or more such monsters reaching down to its core. You can see why this can’t be a good thing. Your computer may slow down to the point where it cannot even be operated. It’s been known to happen, because many people think that having extra antivirus programs means having extra protection.
Another thing that may happen when running more than just one antivirus on one computer is that they can actually interfere with each other and reduce each other’s efficiency. One antivirus can actually make a mistake of recognizing the other as a threat, and this is, again, not something that companies do in fear of competition. It’s simply because antivirus is authorized to perform activities which can be viewed by other antivirus as suspicious. This is just one kind of false positives that antivirus developers have to deal with, and whitelists can help to a certain degree, but not always.
Furthermore, some antivirus programs are not only incompatible, but they are downright not at all functional with other antiviruses. They simply shut down and stop working. Now, if you have two antiviruses, and they are both “allergic” to each other, imagine what can happen? They can both crash and stop working, leaving you with no protection at all, instead of double protection, as was your intention.
Another thing that happens a lot to those that follow the “two antiviruses is better than one” mantra is that, when their software detects a threat, or they themselves suspect there was a breach and a virus got in, they panic and install one or more other antivirus programs, usually free antiviruses or free trial versions of paid antiviruses. The system, which was doing fine up until that point, slows down to a point where the only thing you can do is perform system restore. And everyone who has ever done a system restore knows what this means. It’s a very bad idea. If you think the antivirus you have installed is not doing its job, instead of throwing a bunch of other software onto your poor computer’s back, try contacting the AV company’s tech support. They will walk you through the process and help you identify and isolate the virus, if there even is one in the first place.
The bottom line is – it is never a good idea to install more than one antivirus on your computer. If you are not happy with your AV software, uninstall it and get new one. But make sure to do it in that particular order. Do not install new software until you have uninstalled the previous one. Sometimes, several antiviruses on one computer interfere with each other in a way that makes it difficult to even uninstall one or more of them. The best way to go around this is to use the software’s own uninstall wizard. Do not just delete the program from the list.