How to scan or check for computer viruses
The best method to check and protect a computer for computer viruses is to use an antivirus program. Many antivirus programs are available to choose from, but the better-rated brands are Kaspersky, Symantec, Trend Micro, and MSE (Microsoft Security Essentials). You can get a basic antivirus program or a full antivirus suite, which often include other types of protection beyond only virus protection. You can also try using a free online virus scanner to check for viruses on your computer.
See the additional information section at the bottom of this page for a list of antivirus programs.
How do they work?
Each antivirus program has a different user interface, but they'll make a Scan option/button readily visible. Clicking the button should begin the process. Although you may have other options before the scan begins, including the option for both a quick and full scan. A quick scan searches the most common areas attacked by viruses and takes less time than the full option. However, a full scan is a better choice to run first as it ensures the program checks all possible places on your computer for viruses.
What happens if the program locates a virus?
After completing a scan, the antivirus program displays the results of the scan and any detected viruses. If the program has not already done so, it should ask to proceed with removing the viruses or if they should be quarantined.
Other benefits of an antivirus
Most antivirus programs can schedule virus scans to run at a selected time each day, week, or month, or only scan the computer when it's on but not being used. Also, after installing an antivirus program, the program stays open in the background and scans files as they are open, downloaded, or executed.
How to prevent viruses
There are also several steps everyone using your computer should follow to help prevent any viruses or other malware from infecting your computer. See the below document for information about how viruses infect a computer.