Having your antivirus program scan the entire computer for viruses is a necessity. Even though most antivirus programs have an auto-protect feature that should -- theoretically -- prevent the insertion of a virus onto your computer, it’s still a good idea to scan your computer periodically in the event something was missed somehow by the automatic protection.

When scheduling periodic scans, choose a day and time when you know your computer will be running. It’s no good to schedule a scan for Friday night at 10:00 p.m. if your computer is turned off. If your computer is in standby or hibernation mode (common battery-saving modes on laptops), your antivirus program will not wake it up to scan. It’s got to be fully awake and running at the appointed time. On the plus side, your monitor needn’t be on.

One other factor to take into account for your weekly scan: Run it when your computer is running but when you’re not using it. If you have one of those high-speed Internet connections (such as cable or DSL), then perhaps you keep your computer on all the time anyway. If so, then you can just schedule your scan to take place, say, on Fridays at 1:00 a.m. (or whenever you’re routinely not using the computer).