Computer Hardware and Networking Interview Questions and Answers

---

Introduction

COMPUTER HARDWARE AND NETWORKING INTERVIEW QUESTIONS 2026

Computer Hardware and Networking are core areas for IT support engineers, system administrators, network technicians, helpdesk professionals, and freshers preparing for interviews. Interviewers test not only theoretical knowledge but also practical understanding, troubleshooting ability, and real-world scenarios.

This document provides detailed computer hardware and networking interview questions with clear answers, suitable for:

• Freshers
• Experienced candidates
• IT support / Desktop support roles
• Network engineers
• System administrators

---

PART 1: COMPUTER HARDWARE INTERVIEW QUESTIONS

COMPUTER HARDWARE AND NETWORKING INTERVIEW QUESTIONS 2026

---

1. What is computer hardware?

COMPUTER HARDWARE AND NETWORKING INTERVIEW QUESTIONS 2026Answer:

Computer hardware refers to the physical components of a computer system that can be seen and touched. Examples include the CPU, motherboard, RAM, hard disk, monitor, keyboard, mouse, printer, and power supply.

---

2. What are the main components of a computer?

Answer:

The main components of a computer are:

• Central Processing Unit (CPU)
• Motherboard
• Random Access Memory (RAM)
• Storage devices (HDD, SSD)
• Power Supply Unit (PSU)
• Input devices (keyboard, mouse)
• Output devices (monitor, printer)

---

3. What is the CPU?

Answer:

The CPU (Central Processing Unit) is the brain of the computer. It performs all calculations, executes instructions, and manages data processing.

---

4. What are the parts of a CPU?

Answer:

The CPU consists of:

• Arithmetic Logic Unit (ALU) – Performs arithmetic and logical operations
• Control Unit (CU) – Directs all operations of the computer
• Registers – Small, fast memory inside the CPU

---

5. What is RAM?

Answer:

RAM (Random Access Memory) is temporary memory used to store data and programs currently in use. Data in RAM is lost when the computer is turned off.

---

6. Difference between RAM and ROM

RAM	ROM
Volatile	Non-volatile
Temporary storage	Permanent storage
Faster	Slower
Data lost on power off	Data retained

---

7. What is ROM?

Answer:

ROM (Read Only Memory) stores firmware and boot instructions required to start the computer.

---

8. What is a motherboard?

Answer:

The motherboard is the main circuit board that connects all hardware components such as CPU, RAM, storage, and expansion cards.

---

9. What is BIOS?

Answer:

BIOS (Basic Input Output System) initializes hardware during startup and loads the operating system.

---

10. What is UEFI?

Answer:

UEFI (Unified Extensible Firmware Interface) is a modern replacement for BIOS with faster booting, better security, and support for large disks.

---

11. What is a hard disk?

Answer:

A hard disk is a permanent storage device used to store operating systems, software, and user data.

---

12. Difference between HDD and SSD

HDD	SSD
Mechanical parts	No moving parts
Slower	Faster
Cheaper	Costlier
More power consumption	Less power

---

13. What is cache memory?

Answer:

Cache memory is high-speed memory located close to the CPU to store frequently accessed data.

---

14. What are input devices?

Answer:

Input devices are used to enter data into the computer, such as keyboard, mouse, scanner, webcam, and microphone.

---

15. What are output devices?

Answer:

Output devices display results from the computer, such as monitor, printer, speakers, and projector.

---

16. What is a power supply unit (PSU)?

Answer:

PSU converts AC power into DC power and supplies it to computer components.

---

17. What is a graphics card?

Answer:

A graphics card processes visual output and sends it to the monitor. It is essential for gaming, video editing, and graphics work.

---

18. What is CMOS?

Answer:

CMOS stores BIOS settings such as date, time, and hardware configuration.

---

19. What is overheating?

Answer:

Overheating occurs when hardware components exceed safe temperature limits, causing performance issues or shutdowns.

---

20. How to prevent overheating?

Answer:

• Clean dust regularly
• Ensure proper ventilation
• Use cooling fans
• Replace thermal paste

---

PART 2: TROUBLESHOOTING INTERVIEW QUESTIONS

---

21. Computer not turning on – what will you check?

Answer:

• Power cable
• Power supply
• SMPS fan
• Motherboard LED
• RAM seating

---

22. No display on monitor – reasons?

Answer:

• Loose VGA/HDMI cable
• Faulty RAM
• Graphics card issue
• Monitor problem

---

23. What is POST?

Answer:

POST (Power-On Self-Test) checks hardware components when the computer starts.

---

24. Beep codes indicate what?

Answer:

Beep codes indicate hardware errors such as RAM, processor, or motherboard failure.

---

25. Blue Screen of Death (BSOD) means?

Answer:

BSOD indicates critical system errors caused by drivers, hardware failure, or OS corruption.

---

26. System running slow – possible reasons?

Answer:

• Low RAM
• Malware
• Full hard disk
• Background programs

---

27. What is device driver?

Answer:

A device driver allows the operating system to communicate with hardware devices.

---

28. What is formatting?

Answer:

Formatting prepares a storage device to store data by creating a file system.

---

29. Difference between quick format and full format

Answer:

Quick format removes file references, while full format checks disk sectors.

---

30. What is antivirus?

Answer:

Antivirus software protects the system from viruses and malware.

---

PART 3: NETWORKING INTERVIEW QUESTIONS

COMPUTER HARDWARE AND NETWORKING INTERVIEW QUESTIONS 2026

---

31. What is computer networking?

Answer:

Networking connects multiple computers to share data and resources.

---

32. Types of networks

Answer:

• LAN (Local Area Network)
• MAN (Metropolitan Area Network)
• WAN (Wide Area Network)

---

33. What is LAN?

Answer:

LAN connects computers within a limited area like an office or building.

---

34. What is WAN?

Answer:

WAN covers large geographical areas, such as the Internet.

---

35. What is an IP address?

Answer:

An IP address uniquely identifies a device on a network.

---

36. IPv4 and IPv6 difference

Answer:

IPv4 uses 32-bit addresses, IPv6 uses 128-bit addresses.

---

37. What is MAC address?

Answer:

MAC address is a unique physical address assigned to a network interface card.

---

38. What is a router?

Answer:

A router connects multiple networks and routes data packets.

---

39. What is a switch?

Answer:

A switch connects devices within a LAN and forwards data efficiently.

---

40. Hub vs Switch

Answer:

Hub broadcasts data to all ports, while switch sends data only to the destination.

---

41. What is DNS?

Answer:

DNS converts domain names into IP addresses.

---

42. What is DHCP?

Answer:

DHCP automatically assigns IP addresses to devices.

---

43. What is subnet mask?

Answer:

Subnet mask divides IP addresses into network and host parts.

---

44. What is gateway?

Answer:

Gateway connects different networks.

---

45. What is ping command?

Answer:

Ping checks network connectivity.

---

46. What is firewall?

Answer:

Firewall protects the network by filtering traffic.

---

47. What is proxy server?

Answer:

Proxy acts as an intermediary between users and the internet.

---

48. What is bandwidth?

Answer:

Bandwidth is the data transfer capacity of a network.

---

49. What is latency?

Answer:

Latency is the delay in data transmission.

---

50. Difference between TCP and UDP

Answer:

TCP is reliable and connection-oriented, UDP is faster and connectionless.

---

Conclusion

Computer Hardware and Networking interview preparation requires strong fundamentals, troubleshooting skills, and practical knowledge. These questions cover essential topics commonly asked in interviews for freshers and experienced professionals.

Practicing these questions will improve confidence and increase chances of success in IT job interviews.

---

COMPUTER HARDWARE AND NETWORKING INTERVIEW QUESTION QUIZ TO  CLICK HERE