CompTIA A+ Core 1 (220-1201)Hardware and Network TroubleshootingHard
A technician configures a workstation to boot from a USB installation drive, but the system continually boots directly into the existing Windows installation instead, even after changing the boot order in the BIOS/UEFI setup. The USB drive was verified to be bootable on another machine. Which setting is MOST likely preventing the USB boot?
- AFast Boot is disabled in UEFI settings
- BThe system clock is set to the wrong time zone
- CThe workstation's TPM chip has been disabled
- DSecure Boot is enabled and blocking the unsigned USB bootloader
Show answer & explanationAnswer & explanation
Correct answer: D. Secure Boot is enabled and blocking the unsigned USB bootloader
UEFI Secure Boot only allows boot loaders with valid digital signatures; many USB installation media created with certain tools or containing unsigned/legacy bootloaders will be blocked, causing the system to fall back to the existing signed Windows bootloader even if boot order lists the USB drive first. Disabling Secure Boot (or ensuring the media is properly signed) typically resolves this.
Why the other options are wrong
- A. Fast Boot being disabled would not prevent USB media from booting; it mainly affects boot speed and device initialization.
- B. An incorrect time zone has no effect on which boot device is selected.
- C. TPM being disabled affects encryption features like BitLocker, not boot device selection.
Secure Boot Blocking USB Media
UEFI Secure Boot verifies digital signatures on boot loaders and will prevent unsigned or improperly prepared USB installation media from booting, even if listed first in boot order.
- Secure Boot requires signed bootloaders
- Can block legitimate but unsigned USB installers
- Temporarily disabling Secure Boot often resolves the issue
Memory trick: Secure Boot is a bouncer — no signature, no entry, no boot.