The word virus is often used to describe three different types of computer infections: worms, trojans and viruses. These are malicious programs that get installed on a computer, often without the knowledge of the user, and can lead to privacy being invaded and/or data being destroyed or corrupted on users’ hard drives.
These infections are primarily spread in the following ways:
Viruses: via e-mail attachments and file sharing
Worms: by being connected to the Internet without effective protection (read on for more info)
Trojans: by visiting corrupted web sites
Symptoms of Problems
Symptoms of an infected computer include:
Computer is unstable and crashing frequently
Slow Internet connection
You receive a call from your Internet technical support alerting you of the situation
Install a virus-checking program, and keep it up-to-date. It is worth noting that some viruses will disable virus checkers and you may need to try a few different programs to find and remove an infection.