While one antivirus program is a must for every computer user to stay protected against viruses, malware and other maladies of the internet, Patrick Marshall writes on a Seattle Times Q&A that using two is not recommended.
Reader John Hahn from Woodinville, Washington, wrote in and said he tried running two programs and encountered problems.
"It's generally not a good idea to run two antivirus programs on the same computer, and virtually all antivirus programs warn against doing so," Marshall said. "Antivirus programs monitor your computer's behavior for signs of viruses. The problem is that some of those monitoring activities can look like virus activity. So one antivirus program can appear to another as a virus."
He said even if people don't run into conflicts, they may see a big decrease in the performance of their computer, as two antivirus programs could drain the amount of memory a computer has to use.
Security-FAQs said using more than one antivirus program will either block either or try to eliminate one another. Instead of having two programs battling, research and pick one to protect the computer from viruses, malware and more.