Quick Answer
The correct answer is disk error because a disk boot failure cause is almost always rooted in the storage subsystem, not in memory, power, or network components. When the system displays this error, it means the BIOS or UEFI firmware has completed its power-on self-test but cannot locate a valid boot sector or operating system loader on the designated hard drive. This typically results from a corrupted master boot record, physical bad sectors, a loose or faulty data cable, or a drive that has simply failed. On the CompTIA ITF+ FC0-U61 exam, this question tests your ability to interpret common POST error messages and isolate hardware failures; a common trap is confusing this with a memory or power issue, but the phrase “boot failure” always points to the disk. Remember the memory tip: “Boot is disk, not blips”—if the screen says boot failure, check the drive and its connections first.
This FC0-U61 practice question tests your understanding of it concepts and terminology. The scenario asks you to isolate a root cause — eliminate options that address a different problem before choosing. After answering, compare your reasoning against the explanation and wrong-answer breakdown below. Once you have made your selection, read the full explanation to reinforce the concept and understand why each distractor is designed to mislead on exam day.
Refer to the exhibit. Server log entry: [ERROR] Disk write failure at sector 0x3F2. System halted.
Based on the exhibit, what is the most likely cause of the error?
Clue words in this question
Noticing these words before you look at the options changes how you read each choice.
Clue: "most likely"
Why it matters: Probability qualifier — the question wants the most probable cause or outcome, not a guaranteed one. Eliminate low-probability options.
Refer to the exhibit. Server log entry: [ERROR] Disk write failure at sector 0x3F2. System halted.
Network outage
Why wrong: Network issues would not cause disk write errors.
Power supply failure
Why wrong: A failing power supply usually causes random shutdowns, not specific disk errors.
Bad memory stick
Why wrong: Memory errors typically show different messages.
Disk error
The error states a disk write failure.
Answer choices
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
Disk error
The exhibit shows a 'Disk Boot Failure' or similar error, which indicates the system cannot find a valid boot sector on the hard drive. This is most commonly caused by a disk error, such as a corrupted master boot record (MBR), bad sectors, or a disconnected data cable. Option D is correct because the error message directly points to a storage device issue, not a network, power, or memory problem.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Answer analysis
For each option: why learners choose it and why it is or isn't the right answer here.
Network outage
Why it's wrong here
Network issues would not cause disk write errors.
Power supply failure
Why it's wrong here
A failing power supply usually causes random shutdowns, not specific disk errors.
Bad memory stick
Why it's wrong here
Memory errors typically show different messages.
Disk error
Why this is correct
The error states a disk write failure.
Clue confirmation
The clue word "most likely" in the question point toward this answer.
Related concept
Read the scenario before looking for a memorised answer.
Common exam traps
The trap here is that candidates may confuse a 'Disk Boot Failure' with a memory or power issue because they all can cause the system to fail to start, but the specific error message isolates the problem to the storage device.
Trap categories for this question
Command / output trap
Memory errors typically show different messages.
Detailed technical explanation
The 'Disk Boot Failure' error occurs when the BIOS/UEFI completes POST but cannot locate a bootable device, often due to a corrupted MBR (sector 0) or a missing bootloader like NTLDR (Windows) or GRUB (Linux). In real-world scenarios, this can also happen if the boot order is misconfigured in BIOS, or if a secondary drive with no OS is set as the first boot device, causing a false disk error.
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
A practitioner preparing for the FC0-U61 exam encounters this exact type of scenario on the job. The correct answer here is not the most general option — it is the best answer for the specific constraint described. Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option. Real exam questions reward reading the full scenario before eliminating options, because the constraint defines which answer fits.
What to study next
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
IT Concepts and Terminology — study guide chapter
Learn the concepts, then practise the questions
IT Concepts and Terminology practice questions
Targeted practice on this topic area only
All FC0-U61 questions
512 questions across all exam domains
CompTIA ITF+ FC0-U61 study guide
Full concept coverage aligned to exam objectives
FC0-U61 practice test guide
How to use practice tests most effectively before exam day
Related practice questions
Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.
Practise FC0-U61 questions linked to IT Concepts and Terminology.
Practise FC0-U61 questions linked to Infrastructure.
Practise FC0-U61 questions linked to Applications and Software.
Practise FC0-U61 questions linked to Software Development Concepts.
Practise FC0-U61 questions linked to Security.
Practise FC0-U61 questions linked to Database Fundamentals.
Practise FC0-U61 questions linked to FC0-U61 fundamentals.
Practise FC0-U61 questions linked to FC0-U61 scenario.
Practise FC0-U61 questions linked to FC0-U61 troubleshooting.
Practice this exam
Short sessions build daily habit. Longer sessions build exam-day stamina. Try a timed session to simulate real conditions.
FAQ
IT Concepts and Terminology — This question tests IT Concepts and Terminology — Read the scenario before looking for a memorised answer..
The correct answer is: Disk error — The exhibit shows a 'Disk Boot Failure' or similar error, which indicates the system cannot find a valid boot sector on the hard drive. This is most commonly caused by a disk error, such as a corrupted master boot record (MBR), bad sectors, or a disconnected data cable. Option D is correct because the error message directly points to a storage device issue, not a network, power, or memory problem.
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Yes — watch for: "most likely". Probability qualifier — the question wants the most probable cause or outcome, not a guaranteed one. Eliminate low-probability options.
Read the scenario before looking for a memorised answer.
About these practice questions
Courseiva creates original exam-style practice questions with explanations and wrong-answer analysis. It does not publish real exam questions, exam dumps, or protected exam content. Learn why practice questions differ from exam dumps →
Last reviewed: Jun 25, 2026
This FC0-U61 practice question is part of Courseiva's free CompTIA certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the FC0-U61 exam.
Question Discussion
Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.
Sign in to join the discussion.