Which action is not recommended for maintaining system cooling?

Removing unused expansion card slot covers is not recommended for maintaining system cooling because it can lead to an increase in dust intake and disrupt the airflow within the case. While it's common practice to keep components and airflow paths clear, leaving those slots open does not serve a beneficial purpose for cooling. In fact, it can create more entry points for dust and debris, which can impede cooling efficiency over time.

In contrast, using case fans is crucial for maintaining optimal airflow and heat dissipation, as they actively move air in and out of the case to keep components cool. Keeping dust filters clean prevents dust accumulation on components and ensures that fans can operate efficiently without being obstructed. Properly routing cables inside the case helps to improve airflow by minimizing clutter, allowing air to flow freely and reducing potential hotspots.