Everything else can work in the body but without a brain that person can't really do anything but lie there. In a PC everything is ran by the CPU. Everything must be processed by the Central Processing Unit(CPU) in order to work.

Can a computer run without a CPU?

A motherboard will NOT POST without a CPU. As mentioned earlier, POST is the most initial test a PC performs to check the status of the hardware. ... This is because without a CPU, your video output ports wouldn't even work to display the POST screen!

Does a computer need a CPU?

Every computer needs a motherboard, and every motherboard needs a CPU. The CPU, which stands for Central Processing Unit, determines how much data a computer can handle at one time and how quickly it can handle that data.