You want to upgrade a single-core processor to a dual-core. What is necessary?

To upgrade from a single-core processor to a dual-core processor, replacing the existing processor is the necessary action. Processors are designed with a specific architecture and socket type that fits into the motherboard. A dual-core processor will have different specifications and features compared to a single-core processor, and it must be physically installed in place of the original processor.

Simply upgrading components like the graphics card or adding more RAM would not affect the core count of the processor. While upgrading the motherboard may be necessary in some cases if the existing motherboard does not support dual-core processors, it is not inherently required for every upgrade scenario, as some motherboards can directly support dual-core processors with just a simple CPU replacement. Therefore, replacing the existing processor is the most straightforward and direct approach to achieving the goal of upgrading to a dual-core processor.