Antivirus Programs offer Virus Protection and Removal.

Antivirus programs are created to protect your computer from viruses. Computer viruses are basically program modifications made to certain files that are designed to replicate on their own (say, when the host program file is executed). Viruses may or may not have a "payload" - a set of instructions that may be executed only under certain conditions, such as a particular date each year or after so many file "infections". These instructions can range anywhere from displaying a message on the screen to reformatting your hard drive or otherwise disabling (and, yes, damaging) your system. All viruses (destructive or not) rob your system of computing resources and have the potential of interfering with the normal functioning of your system. Antivirus programs are needed to ensure virus detection, protection and removal.

Antivirus programs are available that are designed to detect and remove or disable most of these viruses. Once properly installed, these programs can scan your system for viruses and in most cases remove them from your system. (Some types of viruses cannot be removed, except by deleting the infected files and replacing them with uninfected copies.) These programs then remain on the system to automatically scan incoming files (e.g., from a diskette or across the network) for new viruses.

Virus scans are a simple first step towards virus protection.

Many reputable antivirus programs offer a  FREE online, on-demand virus scanner.  Often they require that you submit your name and email address. They then launch a new page where you can download a free scan program to scan your computer for viruses.  These online free virus scans will only scan your computer for viruses that may be on it right now. They will not detect a new virus that arrives the following day.. For that you need full-time virus protection that come with disk-resident antivirus programs.