Many antivirus programs — including Symantec Norton Antivirus and McAfee VirusScan — have an autoprotect feature that will protect your computer in real time. In such cases, the antivirus program will automatically quarantine anything it suspects to be a virus.

That said, if your antivirus software doesn't offer an autoprotect feature and you suspect you have a virus, the first thing you should do is run a virus scan using your antivirus software. If you have no viruses, follow the directions to update your virus definition files and run a second scan. Still no viruses? You're probably in the clear. Go ahead and back up important files and reboot. If there were no problems, chances are you're safe.

It's tempting — if you think you have a virus — to immediately back up all of your files onto a server, disc, or other media for safekeeping. The problem? If you don't know what virus you have, you may be backing up and transferring it as well. Viruses are one of the many reasons you should have a comprehensive data backup plan to minimize data loss in the event something very, very bad happens to your computer.