Which of the following does NOT contribute to securing a system?

Disabling user account control is the action that does not contribute to securing a system. User Account Control (UAC) is a security feature in Windows that helps prevent unauthorized changes to the operating system. It does so by prompting for permission or an administrator password before allowing actions that could potentially affect system stability or security. When UAC is disabled, it opens up the system to more vulnerabilities, as any application can make changes without user consent or administrative oversight, leading to increased risk of malware infections or unintended system modifications.

In contrast, installing encryption software protects data by ensuring that sensitive information is unreadable to unauthorized users, implementing a firewall controls incoming and outgoing traffic to prevent unauthorized access, and regularly updating security software ensures that the latest threats are recognized and mitigated. All these actions actively enhance the security posture of a system, making the choice of disabling UAC particularly detrimental to maintaining security.