What is the most cost-effective upgrade for a school library's existing computer?

Increasing the memory is often the most cost-effective upgrade for a school library's existing computer because it directly impacts the performance and efficiency of the system. More memory allows the computer to run more applications simultaneously and improves the speed at which processes are executed, making it particularly beneficial for handling multiple users or applications typical in a school environment.

This upgrade can significantly enhance the user experience without the need for a complete system overhaul, making it an economical choice. Upgrading memory typically requires less technical skill than replacing hardware components like hard drives or installing operating systems and software, which may come with compatibility issues or higher costs.

In contrast, replacing the hard drive can be more expensive and labor-intensive, especially if data migration is needed. Installing a new operating system can also involve costs and complications, including the need for training users on the new system. Upgrading software applications, while beneficial for functionality, is often contingent upon the existing memory capacity; if the hardware cannot support the new applications well, it may not yield the desired improvements in performance. Thus, increasing memory stands out as the most straightforward and effective approach for an immediate performance boost in most situations.