A presentation on computer viruses was given by Farid uddin bhuiyan. The presentation defined a computer virus as a program that damages computer systems and destroys or erases data files. It described seven common types of computer viruses and explained how viruses work by exploiting vulnerabilities on interconnected systems. Signs of a virus infection were provided, such as unusual screen messages or slowed computer performance. The presentation concluded by recommending ways to prevent virus infections, such as keeping anti-virus software updated weekly and backing up important files.