Comprehensive and Detailed Explanation From Exact Extract (Aligned With CompTIA A+ 220-1201 Study Guide)
When installing an operating system from external media (USB flash drive), the motherboard firmware must be instructed to check that device before checking the internal storage.
The CompTIA A+ official objectives describe that technicians must know how to access UEFI/BIOS settings and configure boot priority. Installing an OS from USB requires:
Entering UEFI/BIOS setup
Navigating to the Boot or Startup menu
Setting the USB drive as the first boot device
Saving and exiting to allow the computer to boot from the USB installer
This process is specifically referenced in CompTIA A+ material under “BIOS/UEFI settings,” where boot sequence / boot order is a fundamental configuration needed for OS installation.
Thus, the next step after assembling the PC is to modify the boot order to allow the system to boot from the USB installation media.
Why the other options are incorrect
A. BIOS password
Used for system access security; has no relevance to installing an OS from USB.
B. PXE boot
Used for network-based installations, not USB installations.
C. Secure Boot
Controls OS signature validation; not required to be changed for USB installation and is not the next required step.
Final Answer: D
