ITGSS Certified Technology Specialist

What is the correct order of execution for programs when a PC starts?

1. OS, BIOS, resident application programs

2. BIOS, resident application programs, OS

3. Resident application programs, OS, BIOS

4. BIOS, OS, resident application programs

The correct answer is: BIOS, OS, resident application programs

When a PC starts, the correct order of execution involves BIOS first, followed by the operating system (OS), and then resident application programs. The Basic Input/Output System (BIOS) is the first software that runs when the computer is powered on. Its primary function is to perform hardware initialization during the startup process and to load the operating system from the storage device—usually the hard drive or solid-state drive. This process is essential as it sets up the environment in which the OS can operate. After the BIOS completes its tasks, it hands over control to the operating system. The OS is responsible for managing system resources and providing a platform for running application programs. It handles input and output operations, memory management, and allows user interaction with the hardware. Once the operating system has loaded, it can then run resident application programs. These programs are designed to provide specific functionalities and can operate in the background or be launched by the user. This sequence is critical to the successful operation of a computer, ensuring all necessary hardware and software are prepared and functioning before users engage with the applications. Understanding this order helps in troubleshooting startup issues and configuring systems correctly.