Significance

• Antivirus programs are security tools that help protect computer processes and files from malicious activities. There are many antivirus programs available, all with different features, support and scanning options. They run processes in the background to detect and remove dangerous files that do everything from shut down programs to stealing personal information. Because malicious files range from viruses and Trojans to spyware and malware---and come from many angles---installing and running an antivirus program is pivotal.
  
  

Other Antivirus Program

• The presence of an existing antivirus program on your computer causes conflict errors that prevent you from installing another antivirus program. If the antivirus program you are installing stops midway through the installation and states there is a presence of another security tool, uninstall it from your computer from the Control Panel before proceeding. Additionally, it's never a good idea to run more than one trusted antivirus program, because it not only slows down your computer, but limits detection of malicious programs because of conflict errors.
  
  

Compatability

• Before installing an antivirus program, make sure that your computer hardware and configurations are suitable to work with it, otherwise the installation will fail. If the antivirus program you are trying to install, for example, requires at least 2GB of RAM and you only have 256MB, then the installation will likely fail. In the event that it does go through, you are likely to run into constant freezing and crashing issues. Make sure that the antivirus program you are trying to install is compatible with your computer's "Service Pack." If it is intended for "Service Pack 2" and you have "Service Pack 3," chances are you will run into installation errors.
  
  

Malicious Programs

• Antivirus program installations fail when a malicious program makes its way into the system prior to the antivirus program installation. Strong viruses and Trojans disable the security center on your computer and change the registry settings to prevent you from installing an antivirus program. They also hijack the "Start-up" feature and automatically launch every time you start your computer. In order to eventually install the antivirus program, you may need to perform a manual removal of the malicious files. Because this can be extremely difficult, it is best to take your computer to a technician for troubleshooting.
  
  

Warnings

• Always install an antivirus program before you use the Internet to avoid accidentally installing malicious files that will later prevent you from installing an antivirus program. Do not download or attempt to install antivirus programs that you are not familiar with, because there are many rogue antivirus programs out there, such as Antivirus 2009, that camouflage as legitimate security tools but instead trick you into paying money for a useless program. There are many credible companies, such as AVG, Norton and Kaspersky, that offer legitimate antivirus programs.