Transcription: A computer virus is a program intended to destroy systems by corrupting or erasing data. Disquets, networks, and modem transfers can carry viruses. When programs from an infected computer are used on another system, the virus spreads. Problems might occur as soon as the virus invaded the system, or the virus might wait for a preset time before becoming active. To protect your system, use virus-checking software to scan diskettes and new files before before copying or using them. Use only write protected master copies to make backups. Make copies after you start up with a write protected disk. ...