• Think before you click.
  Before opening attachments or clicking on links you receive through e-mail, it's a good idea to contact the sender to be sure that they 1) created the file themselves and 2) sent the file to you intentionally. Viruses usually send themselves without any participation from the person whose name is listed as the message originator.
   
• Choose to view those file extensions!
  The default Windows configuration hides "common file extensions," like .EXE and .SCR that are commonly virus extensions, from your view. Therefore, an attachment with a name like "pictures.gif.scr" will appear in your email with the name "pictures.gif" — leading you to believe that the attachment is simply a GIF image when it is in fact a virus. To change this default setting in Windows 98 and above:
  
  
  1. Launch Windows Explorer (either from your Start menu or your desktop);
  2. In Windows Explorer, choose "Folder Options..." from the "Tools" menu;
  3. In the window that opens, click the "View" tab;
  4. Then, deselect the option in the list that says: "Hide file extensions for known file types";
  5. Click "OK" to accept this change.
  
  To change this default setting in Windows 95:
  
  
  1. Launch Windows Explorer (Start->Programs->Windows Explorer)
  2. In Windows Explorer, choose "Options" from the "View" menu;
  3. In the window that opens, deselect the bottom options that says: "Hide MS-DOS file extensions for file types that are registered";
  4. Click "OK" to accept this change.
  
   
• Install an antivirus (AV) program.
  These days, many systems come with an antivirus program pre-installed and, of course, you can always pay companies such as McAfee, Symantec (Norton), Computer Associates, or Sophos for their products. However, there are some free AV programs, like Finjan’s Surfin' Guard, that have received high marks. Note that InoculateIT Personal is no longer available, but virus definition file updates can be obtained.
   
• Update, update, update.
  Regularly update your virus software (see above links to the most common websites.) As new viruses are detected, vendors of AV software release updated virus definitions or signature files that will detect and clean viruses. It is highly recommended that you update your software to add these new signature files at least once a month. Exception: Surfin' Guard doesn't require frequent updating.
   
• Back up your data.
  Some viruses contain destructive payloads that can delete all of the data on your hard drive. And though a good, regularly updated AV program will help avoid many problems, it is better to be safe than sorry. A general rule of thumb is to back up any data that you cannot afford to lose onto a ZIP disk, CD-ROM, or floppy disks.
   
• Scan and clean your system.
  Lastly, if you think that you computer has been infected and don't have virus software on your system or simply want a second opinion, you can scan your drives for free on the web at House Call.
   
• Don't believe everything you read.
  Some of the viruses you hear about are hoaxes. What's worse, some of these hoaxes tell you to delete important files from your computer such that you become the virus. Before you follow directions to delete system files or forward the message to all your friends, verify with a reputable source that the "fix" isn't itself the virus.

Information about the latest viruses, what to look for and what damage they can do, can be found at http://www.antivirus.com/.