- Be certain that all power cables and other wired connections running into or out of the computer pass through some kind of surge suppressor. All the antivirus software in the world won't do your computer any good if a lightning strike fries your hard drive.
- Run Windows computers on limited-access accounts.
- Use antivirus software. It's available free via Google Pack for those who refuse to ante up with real money.
- Browse the Internet using something other than the predominant Web browser of the day (which is still Microsoft Internet Explorer, as it has been for years).
- Check e-mail from a webmail account (like Gmail or Yahoo) instead of downloading it directly to the computer.
- Run a backup on your essential data regularly. The easiest method is to copy everything to a portable hard drive stored somewhere away from the computer itself, but recordable DVDs and CDs can work, as can off-site Internet storage services.