When is a Windows 10 computer completely secured?

A Windows 10 computer being "completely secured" is an ongoing process rather than a definitive endpoint, which is why the notion described in the answer is accurate. Security is a multifaceted issue that evolves over time with new threats and vulnerabilities emerging regularly. Focusing on the idea of a computer being completely secure at any point in time doesn't account for the fact that as software develops and new exploits are discovered, an unchanging system could become susceptible to unknown risks.

While keeping the system updated with the latest version and security patches is crucial to maintaining security, the landscape of cyber threats is constantly changing. Options that suggest a state of completion, like an update or a locked security policy, do not take into account future threats or vulnerabilities that could arise after those actions are taken.

Therefore, the understanding that a computer is never wholly secured reflects the necessity for continuous vigilance, regular updates, and the adoption of best practices in security to adapt to an ever-evolving threat landscape.