This document discusses computer viruses including how they spread, their symptoms, and how to prevent them. It notes that viruses can spread through USB drives, CDs, floppy disks, and the internet. Symptoms include programs taking a long time to load, the computer slowing down, unusual messages, file extension changes, and files becoming inaccessible or deleted. The document recommends downloading antivirus software and updating it, only loading software from original disks, using passwords, backing up files, and not downloading unknown programs or opening emails from strangers. It also includes some sample quiz questions about computer viruses.