Viruses are an inescapable part of the Internet experience. Depending on the virus, the effect can range from benign to devastating. When it comes to dealing with the dangers posed by viruses, prevention is much easier than repair and or data loss. The following tips will help prevent most viruses from ever affecting your computer system.

1. Beware of unexpected or unsolicited email attachments
   Email is one of the primary ways to exchange information, it is also a key method used for spreading viruses. A basic plain text email is unable to transmit most viruses. It is the attachment to the email that contains the potential hazard. If the attachment is unexpected or unsolicited and from an unknown sender, the wisest decision would be to delete the email without opening the attachment. If the email is from a known and trusted source, but you did not expect an attached file from that source, you may want to contact the sender to confirm that the attachment is legitimate before opening.

2. Use an anti-virus program to regularly scan your computer
   Even if you exercise reasonable caution, you may still be infected by a virus. An anti-virus program can be set up to regularly check your computer or even your incoming email attachments for viruses. This kind of program may even be able to constantly run in the background as you go about your work. Because viruses are being constantly created or changed, it is very important to use a program that provides regular updates.

3. Use an anti-virus program to scan all incoming email attachments and all files or programs that came from someone else's computer.
   Whenever someone puts a file or a program on their computer, there is always some risk that some virus may infect that file or program and remain undetected. By scanning all incoming files and programs, you may uncover a virus that the other person may have overlooked. Even if someone hands you a file or program on media such as a floppy, cd or usb memory stick, it could be infected.

4. Update your anti-virus program regularly
   New or improved viruses are being regularly unleashed on the Internet. Updating your anti-virus software so that it contains the latest virus definitions will decrease the likelihood that you are affected by a new type of virus.

5. Back up your data files on a regular basis
   In a worst case scenario, a virus may corrupt or destroy data on one or more files. Regular backups will allow you to recover this data more easily in the event that a virus damages your files.

6. Purchase or obtain files or software only from trusted sources
   When a retailer offers new software at a price that is much lower compared to the manufacturer's prices or prices charged by most retailers, that software is suspect and most likely is not an authorized copy. This kind of software poses many risks, including a higher risk of having one or more viruses. This tip is relevant to software or files that are downloaded over the Internet, that come as attachments to email, or that is purchased at a store.

7. Avoid forwarding email attachments unless you first scan the attachment for viruses
   If you have an anti-virus program that scans all incoming email attachments, or if you scan the attachment after it arrives, then it is probably safe to forward the attachment. Otherwise, do not forward the attachment.

8. Look for an unexpected file extension on any attachment
   If the subject line or the body of an email states that the attachment is a certain type of file or if the file icon implies a certain type of file and the file extension does not match, delete the file. If you trust the sender, contact that person to determine what you were supposed to have received. Some people will send attachments as zip files containing one or more regular files in the zip archive. Each one of these files contained in the zip archive could be infected. Most of the latest anti-virus software is capable of examining each individual file contained in zip style archives.

9. Data files can carry viruses
   Some files that contain only data may carry a virus that exploits flaws in the operating system of the computer. Usually files that don't contain viruses are files ending with the extension .txt, .csv, .gif, .jpg, .mp3, since the usually don't contain executable code. However, some files like .gif and .jpg have been known to exploit flaws in your computers operating system to try and execute code. It's important to keep your operating system up to date with the latest security patches.

   Virus Resources
   Free virus scanner:  AVG
   McAfee.com Virus Information Library and alphabetical listing
   Symantec AntiVirus Research Center
   National Infrastructure Protection Center
   Virus Information from Webopedia