A computer can't boot if it does not have ____________

Booting is the process by which a computer starts up and becomes ready for use. When power is switched on, the hardware first runs a small built-in startup routine, but that routine's main job is to locate and load a larger program that will manage the whole system from that point onward.

That larger program is the operating system, OS, which controls hardware resources, manages files, and provides the environment in which other software, including compilers, assemblers, and loaders, can run. Without an operating system installed and loadable, the startup process has nothing to hand control over to, so the computer cannot complete booting into a usable state.

Compilers, assemblers, and loaders are useful programs for translating and preparing other software, but none of them manage the overall running of the machine the way an operating system does, and none of them can substitute for its absence during boot.

Exam takeaway: booting is really the process of loading the operating system, so the operating system is the one component that is indispensable for it to succeed.