How to Check for Viruses

By Jacqui Lane

A virus is a type of malicious software that installs itself on your computer without your consent or knowledge. Viruses are often spread by e-mail attachments or instant messenger links, and can also be disguised in the code of a seemingly normal website. Once installed, a virus can interfere with the operation of your computer, causing it to run slowly, reboot periodically and disable applications, among other effects. Some viruses can also steal personal information that you have stored on the computer and transmit it back to the source. It's a good idea to check for viruses periodically, even if you haven't noticed any unusual "symptoms" on your computer.

Step 1

Choose an antivirus program, if your computer doesn't already have one. There are many different antivirus programs available for free or for purchase. If you don't want to pay for a program, AVG Antivirus Free Edition is rated by as the top free antivirus software. If you want to purchase an antivirus program, ESET NOD32 Antivirus and Norton Antivirus 2009 both received high ratings from ConsumerSearch.

Step 2

Download and install the antivirus program of your choice.

Step 3

Install all of the updates available for the antivirus program you chose. New viruses are created and released every day, and most programs will release updates to detect those viruses on a daily basis. You can choose to manually update your virus definitions, or you can set it to automatically check for updates every so often, usually every 12 or 24 hours.

Step 4

Run a complete virus scan on your entire computer. Depending on the size of your hard drive and the speed of your computer, this can take a few minutes or a few hours. You can usually continue to use your computer while the scan is running in the background.

Step 5

Follow the program's recommendations for any viruses that are detected. You will usually be given an option to quarantine the virus, which moves it to an area where it can't affect other parts of your computer, or to delete it outright.

Tips & Warnings

  • Some viruses may interfere with antivirus programs, or cause your computer to spontaneously reboot, interfering with the scan. If this is the case, reboot your computer and press F8 while it is booting. Select "Safe Mode with Networking" from the boot options. Safe mode will load only the operating system and the drivers necessary for it to function. Run a virus scan in this mode if you can't complete it in regular boot mode.