A systems administrator notices that one of the systems critical for processing customer transactions is running an end-of-life operating system. Which of the following techniques would increase enterprise security?

Placing the system in an isolated VLAN is the most practical and effective immediate security measure. This technique segments the vulnerable system from the rest of the network, limiting its exposure to potential threats while still allowing it to perform its critical function. This is a common strategy for managing legacy systems that cannot be immediately updated or replaced. Installing HIDS (Host-based Intrusion Detection System) on an end-of-life OS might not be fully supported, could introduce instability, or may not detect advanced threats targeting known vulnerabilities in the outdated OS. Decommissioning the system is a long-term solution but isn't feasible if the system is critical for current operations. Encrypting the system's hard drive protects data at rest but does not mitigate network-based vulnerabilities or exploits targeting the outdated operating system itself.