This document discusses how to protect computers from malware through various methods. It recommends installing a firewall, antivirus software, and anti-spyware software to block unauthorized code and protect the system. Common authentication methods for computer access include usernames and passwords, personal identification numbers, access cards, and biometrics like fingerprints. The document also covers the importance of computer ethics and guidelines for ethical computer use, such as respecting privacy, not harming others, and not committing crimes.