BIOS vs UEFI: What A+ Actually Tests
BIOS and UEFI are firmware interfaces. A+ usually tests where you change boot, security, virtualization, and hardware-level settings.
Quick answer
BIOS is the older firmware interface; UEFI is the modern firmware environment with features such as Secure Boot, graphical setup, GPT boot support, and better integration with current systems. For A+, focus on what setting you would check or change.
Start with the setting being changed
If a system will not boot from a USB installer, the exam is probably asking about boot order or boot mode in firmware setup.
If Windows upgrade readiness mentions TPM or Secure Boot, the cue points toward UEFI-era platform security settings.
A+ does not expect firmware engineering. It expects you to know where firmware settings live and how they affect boot, hardware, and security behavior.
- Firmware setup controls boot order, enabled devices, virtualization support, TPM, and Secure Boot.
- UEFI is the modern replacement for legacy BIOS on most current systems.
- Secure Boot helps prevent unauthorized bootloaders from loading.
- TPM support matters for platform security and modern Windows requirements.
BIOS and UEFI compared
BIOS
Best for
Legacy firmware recognition and older boot behavior.
Exam cue
Older system, legacy boot, basic firmware setup.
Common mistake
Assuming every modern platform still behaves like legacy BIOS.
UEFI
Best for
Modern firmware, Secure Boot, GPT boot support, platform security.
Exam cue
Secure Boot, TPM, modern Windows upgrade readiness.
Common mistake
Treating UEFI as a Windows utility instead of firmware.
Boot order
Best for
Choosing which device the system tries first.
Exam cue
Boot from USB, wrong disk starts, no boot device.
Common mistake
Reinstalling the OS before checking firmware boot settings.
Virtualization setting
Best for
Allowing hypervisors or virtual machines to use CPU virtualization.
Exam cue
VM software says virtualization support is disabled.
Common mistake
Troubleshooting the app before checking firmware support.
Scenario cues to look for
A technician needs a PC to boot from a USB installer.
Answer: Check boot order in firmware setup.
Boot order controls the first attempted startup device.
Why not the distractor: This is not primarily a DNS, DHCP, or user-profile issue.
A Windows upgrade check fails because Secure Boot and TPM are disabled.
Answer: UEFI/platform security settings.
Secure Boot and TPM are firmware/platform security cues.
Why not the distractor: Legacy BIOS language is not the best match for current platform security features.
Virtual machine software reports hardware virtualization is disabled.
Answer: Enable virtualization support in firmware.
CPU virtualization settings are commonly controlled in BIOS/UEFI setup.
Why not the distractor: Adding RAM may help VM performance but does not enable the missing feature.
Common exam mistakes
Calling UEFI a Windows setting.
Treat UEFI as firmware accessed before the OS loads.
Skipping firmware when boot behavior is wrong.
Boot order and boot mode are firmware-level checks.
Confusing TPM with storage encryption by itself.
TPM stores and protects cryptographic material; it is not the whole encryption system.
Quick practice questions
Answer each question to reveal the explanation. The full app adds tracked results and weak-area review.
Q1.Where would a technician usually change boot order?
Q2.Which feature is associated with UEFI platform security?
Q3.A VM application says CPU virtualization is disabled. What should be checked?
Ready to test your knowledge?
Try the free CompTIA A+ practice test, or use the app for tracked weak-area review.