Combating Viruses
Two simple precautions can help keep your computer virus free - install and use software from reliable vendors and avoid opening unexpected e-mail attachments.
Almost all e-mail attachments are potential virus carriers. Some of the most famous viruses were distributed by accessing address books of infected computers and sending e-mail (with attachments) to everyone in the address book. Even those from known senders should be regarded with suspicion - e-mail addresses can easily be faked to appear to be from someone you know.