The necessary step in maintaining computer hardware among the options provided is:
D. Cleaning air vents.
Cleaning the air vents on a regular basis is a crucial part of computer hardware maintenance. Dust, dirt, or debris buildup in the air vents can cause overheating problems by obstructing airflow, which may raise the operating temperature of hardware components like the CPU or GPU. This may have an impact on the computer's lifespan and general performance. Maintaining adequate airflow to keep the hardware components operating at peak performance and preventing overheating are two benefits of cleaning the air vents.