Final answer:
The hard drive is not found on a motherboard; it is a separate storage device that connects to the motherboard through cables.
Step-by-step explanation:
The component that is NOT found on a motherboard is the hard drive. While motherboards have slots and connectors for various components, such as RAM (random access memory), CPU (central processing unit), and sometimes even integrated sound cards, the hard drive is typically not mounted directly on the motherboard. Instead, hard drives are connected to the motherboard via cables and are mounted elsewhere in the computer case. Motherboards serve as the main circuit board of a computer and provide the foundation for most other components, but they do not house the hard drive, which is a separate storage device.