Final answer:
The most common PC security risk is malware. Sharing passwords and data entry errors are also risks.
Step-by-step explanation:
The most common PC security risk is malware. Malware refers to any software designed to cause harm or damage to a computer system, such as viruses, worms, or ransomware. Malware can be downloaded unknowingly from websites, emails, or infected files, and it can compromise the security of a PC.
Sharing passwords is also a major security risk (secondary keyword). When passwords are shared, there is a greater chance of unauthorized access to personal accounts or sensitive information.
Data entry errors may lead to security vulnerabilities (secondary keyword) as well. If confidential information is entered incorrectly or mistakenly sent to the wrong recipients, it can result in data breaches or privacy violations.