PC startup configuration: When you change the system start-up boot sequence (for example, USB first, then SSD), which system area are you modifying?

Introduction / Context:
Choosing the order in which a PC searches devices for a bootable OS is fundamental to troubleshooting and deployment. This configuration resides in firmware settings rather than operating system startup files, so technicians must know where to make changes.

Given Data / Assumptions:

• We want to change device priority (e.g., USB, optical drive, NVMe, SATA).
• Modern systems use UEFI/BIOS menus stored in nonvolatile memory (commonly termed CMOS settings).
• Legacy DOS files (CONFIG.SYS, AUTOEXEC.BAT) run after boot begins.

Concept / Approach:

The boot order is set in firmware configuration (BIOS or UEFI). The settings are stored in nonvolatile memory historically called CMOS. CONFIG.SYS, AUTOEXEC.BAT, and COMMAND.COM are operating-system components loaded after a boot device has already been selected; they do not decide which device is attempted first.

Step-by-Step Solution:

Verification / Alternative check:

Use a one-time boot menu to confirm device selection; if the firmware shows the new device order and the system boots accordingly, the change is in effect.

Why Other Options Are Wrong:

• CONFIG.SYS / AUTOEXEC.BAT: Control drivers and environment under DOS after boot begins.
• COMMAND.COM: DOS command interpreter, not the boot selector.
• None of the above: Incorrect because BIOS/CMOS is the correct area.

Common Pitfalls:

Confusing firmware boot order with OS boot loader order; Secure Boot or UEFI-CSM settings interfering; forgetting to save changes before exit.

Final Answer:

BIOS/CMOS