Which precaution helps prevent computers from being infected by a virus?

Using antivirus software in conjunction with the most recent signature files is a crucial precaution for preventing computers from being infected by a virus. Antivirus software is designed to detect, quarantine, and remove malicious software, including viruses, before they can cause harm to the system. The effectiveness of this software hinges significantly on having the most recent signature files, which are databases containing definitions of known viruses and malware. Regular updates to these signature files enable the antivirus program to recognize and respond to new threats that emerge constantly.

Using antivirus software without updated signature files may leave a computer vulnerable to infections by new or variant viruses that the software cannot identify. Thus, maintaining both the antivirus program and up-to-date signature files significantly enhances the computer’s defenses against malware infections.