monster-426993_640Last year I wrote about the importance of having an antivirus scanner on your computer. That hasn’t changed, and I still stand behind my recommendations.

Lately, however, I’ve noticed a trend in the computers I’ve been seeing – more than one antivirus solution has been installed and is running on the computer at the same time. This is a bad idea, and for several reasons. This week, we’re going to be taking a look at why this is, and I’ll show you how to avoid needless hassle – and spending too much money – by using the protection already built in to your copy of windows. In addition, we’ll look at some alternatives to installing a second scanner, if you really feel a second opinion is needed on the possible presence of a virus on your PC.

The first, and perhaps easiest to identify, issue encountered when having more than one antivirus installed is the increased load on system resources – CPU load and memory, in particular. While one antivirus is easily manageable for a modern computer, having two competing for memory space, running scans simultaneously, and looking for updates online can be a real drag on system performance. You’ll notice it in day to day operation of your PC and you’ll REALLY notice it if you try to play a game or use an application that is very resource intensive.

Secondly, aside from competing for resources, the antivirus programs will begin to identify EACH OTHER as potential virus-like programs. Today’s anti-virus programs not only scan for viruses and other malware, they use what are called heuristics – basically a very simple artifical intelligence – to seek out programs which are behaving in a manner perceived as being potentially threatening. When they see another program install itself into memory, access the internet and constantly scan what goes in and out of system memory, of course they will attempt to intervene. The result? Utter confusion as your protection software packages fight to remove and quarantine the other.

Third, if they do somehow find a way to co-exist, they will fight over virus detections and cleaning. One program, for example, may quarantine a potential infected file. The other program will continue to detect that quarantined file and will warn you – repeatedly – of an infected file that needs repairing or cleaning. This unnecessary cycle of detection is caused entirely by the interaction between the two software packages.

Next time, we’ll take a look at alternatives to having more than one antivirus installed on your computer!