Using more than one anti-virus program is not advisable
. The primary concern with doing so is due to conflicts that can arise when they are running in real-time mode simultaneously
. However, even when one of them is disabled for use as a stand-alone scanner, it can affect the other. Anti-virus software components insert themselves into the operating systems core and using more than one can cause instability, crash your computer, slow performance and waste system resources
. When actively running in the background while connected to the Internet, they both may try to update their definition databases at the same time. As the programs compete for resources required to download the necessary files this often can result in sluggish system performance or unresponsive behavior.
Each anti-virus will often interpret the activity of the other as a virus and there is a greater chance of them alerting you to a "False Positive
". If one finds a virus and then the other also finds the same virus, both programs will be competing over exclusive rights on dealing with that virus. Each anti-virus will attempt to remove the offending file and quarantine it. If one finds and quarantines the file before the other one does, then you encounter the problem of both wanting to scan each other's zipped or archived files and each reporting the other's quarantined contents. This can lead to a repetitive cycle of endless alerts that continually warn you that a virus has been found when that is not the case.
Anti-virus scanners use virus definitions to check for viruses and these can include a fragment of the virus code which may be recognized by other anti-virus programs as the virus itself. Because of this, most anti-virus programs encrypt their definitions so that they do not trigger a false alarm when scanned by other security programs. Other vendors do not encrypt their definitions and they can trigger false alarms when detected by the resident anti-virus.
Keep in mind that dual installation
is not always possible because most of the newer anti-virus programs will detect the presence of others and may insist they be removed prior to download and installation of another. Nonetheless, to avoid these problems, use only one anti-virus solution
In contrast, as a general rule, using more than one anti-spyware program like Malwarebytes' Anti-Malware, SuperAntispyware, Spybot S&D, Ad-Aware, etc will not conflict with each other or your anti-virus if using them as stand-alone scanners. In fact, doing so increases your protection coverage without
causing the same kind of conflicts or affecting the stability of your system that can occur when using more than one anti-virus. The overlap of protection from using different signature databases will aid in detection and removal of more threats when scanning your system for malware. However, if using any of their real-time resident shields (TeaTimer, Ad-Watch, Spyware Terminator Shields, etc) together at the same time, there can be conflicts when each application tries to compete for resources and exclusive rights to perform an action. Additionally, competing tools may even provide redundant alerts which can be annoying and/or confusing.
Choosing a security toolkit with anti-virus and anti-malware programs is a matter of personal preference, your technical ability and experience, features offered, the amount of resources utilized, how it may affect system performance and what will work best for your system. A particular combination that works well for one person may not work as well for another. There is no universal "one size fits all
" solution that works for everyone. You may need to experiment and find what is most suitable for your needs. Another factor to consider is whether you want to use paid for
products or free alternatives
However, you can overkill your system with resource heavy security programs that will drain your resources and slow down performance. Sometimes you just have to experiment to get the right combination for your particular system as there is no universal "one size fits all
" solution that works for everyone.