Change the Three Parts That Have to Move Together

A kit exists because a processor, the board that accepts its socket and memory of the generation that board supports cannot be bought separately without risk. Pair them wrongly and the machine will not start. Bought as a set they are matched already, which removes the most common way a piecemeal upgrade goes wrong and usually saves a return.

Everything outside those three parts normally stays where it is. The chassis, power supply, drives, graphics card and often the cooler carry straight over, which is why a kit costs a fraction of a new machine. The value of that depends on the parts you are keeping, so the sections below start with what a new socket demands and end with how long the platform will accept newer chips.