Spyware and viruses can interfere with your computer's ability to process information or can modify or destroy data. You may feel that the more anti-virus and anti-spyware programs you install on your computer, the safer you will be. It is true that not all programs are equally effective, and they will not all detect the same malicious code. However, by installing multiple programs in an attempt to catch everything, you may introduce problems.
It is important to use anti-virus and anti-spyware software (see Understanding Anti-Virus Software and Recognizing and Avoiding Spyware for more information). But too much or the wrong kind can affect the performance of your computer and the effectiveness of the software itself.
Using anti-virus and anti-spyware software is an important part of cyber security. But in an attempt to protect yourself, you may unintentionally cause problems.
Scanning your computer for viruses and spyware uses some of the available memory on your computer. If you have multiple programs trying to scan at the same time, you may limit the amount of resources left to perform your tasks. Essentially, you have created a denial of service against yourself (see Understanding Denial-of-Service Attacks for more information). It is also possible that in the process of scanning for viruses and spyware, anti-virus or anti-spyware software may misinterpret the virus definitions of other programs. Instead of recognizing them as definitions, the software may interpret the definitions as actual malicious code. Not only could this result in false positives for the presence of viruses or spyware, but the anti-virus or anti-spyware software may actually quarantine or delete the other software.
Authors: Mindi McDowell, Matt Lytle