ALWAYS run an up-to-date anti-virus program and use it's real-time protection.

Up-To-Date means that you update the program weekly to make sure the virus definition files are current. You can set up most software to check for updates automatically. Check your software and make sure the virus definitions are current at least once a week. Real-time protection means that your anti-virus program checks all incoming and outgoing files for viruses and stops the transfer of files if it finds one.

NEVER open an e-mail attachment unless you know what it is and who sent it.

Make sure the person that is showing as the sender is the one who sent it. Many viruses will send copies of itself to everyone in the infected users address book. For example, if I had your e-mail in my address book and I opened an infected file and started the virus, it would send you a copy of the virus with me as the sender and it will probably have a subject line you would be interested in. So even if you get an e-mail from me with an attachment, don't open it until you contact me and asked if I sent it to you.

Make sure your system is set to view the entire file name of attachments.

To do that, In Windows Explorer, select 'Tools', 'Folder Options', 'View'. In the dialog box, click the “Hide extensions for know file types” box to uncheck it. Many viruses attempt to hide their identity by adding an additional period and 3 digit extension to the file name. For example, picture.jpg.vbs may appear on your computer as picture.jpg. You think it is a picture file and you open it -- you just started a Visual Basic Script (vbs) virus. NEVER open a file with the .vbs extension unless you know what it does.

.exe Files - Better to be safe than sorry.

There are a lot of legitimate files out there with an extension of .exe. There are also a lot of viruses out there with an extension of .exe. Is it worth taking a chance? If no, delete the e-mail and move on.

If you open an e-mail with an attachment and your computer starts to "act strange", shut it down immediately.

By "act strange", I mean unusual hard drive activity and maybe even a slowing down of the computer. This can be an indication that the virus is sending itself to the people in your address book or damaging files on your hard drive - even formatting it.

The Internet is the number one way of contracting a virus (through e-mails, downloads, and malicious web sites), but it is not the only way.

You can get a virus by downloading files from the internet, or even visiting a malicious web site. The key to survival here is to use caution. If you download files from the internet be sure to scan them for viruses before opening them. If you go to a known hacker site you can expect to get Viruses, Trojans, and be attacked by hackers.
You can also get viruses by inserting and reading infected floppy disks and CD-Rom disks. Before you do anything else, scan these for viruses.

Do not propagate HOAX viruses.

These are not really viruses, but are fictitious e-mails that wander around the internet warning of gloom, doom, and falling skies. They usually tell the reader to "pass this on to everyone you know!". I would estimate that 95% or more of these viruses alerts are a HOAX. Do not send it to anyone unless and until you know for sure that it is legitimate.

Even if you do everything right, you may still get a virus.