What is the most cost-effective way for a school library to upgrade an existing computer with limited funds?

Increasing the memory of an existing computer is often the most cost-effective upgrade for improving performance, especially in a school library setting. Memory, or RAM, plays a crucial role in the speed and efficiency of a computer, particularly when running multiple applications or handling larger files. By upgrading the memory, the computer can process more information simultaneously, which can lead to a significant improvement in its operational efficiency and overall user experience.

This type of upgrade typically involves a lower cost compared to the other options. Adding peripherals like a webcam or an external hard drive can enhance functionality, but they do not directly impact the computer's processing power or speed in the same way a memory upgrade does. Replacing the motherboard is generally the most expensive option, often requiring not just the cost of the motherboard itself but also potentially additional components and labor, which can exceed budget constraints.