// JUNIOR IT SUPPORT — ZERO TO INTERVIEW-READY

Everything you need for this morning

This is a self-contained crash course. Read it top to bottom once, then use the quiz to test yourself. You don't need to be an expert — you need to sound like someone who is calm, logical, and willing to learn. That's 80% of what junior IT interviews actually check for.

00 Your morning plan

You have limited time. Do it in this order.

Read section 01 (Networking) and 04 (Troubleshooting) first — these get asked the most in junior IT interviews.
Skim 02, 03, 05 (Hardware, Software, CCTV) — you just need to recognize terms and give simple correct answers, not deep expertise.
Read section 06 out loud — these are near-exact questions you'll likely be asked.
Take the quiz in section 07 once. Re-read anything you got wrong.
Before you walk in: remember the golden troubleshooting method in section 04 — if you forget everything else, this alone will carry you through most technical questions.

Mindset for the interview

You're applying for a junior role. Interviewers do NOT expect you to know everything. They want to see: (1) you can explain a technical idea simply, (2) you follow a logical troubleshooting process instead of guessing randomly, (3) you're honest when you don't know something and say how you'd find out (Google, documentation, ask a senior). Saying "I haven't worked with that yet, but here's how I'd approach it..." is a great answer.

01 Networking basics

This is the #1 topic for IT support interviews. Master this section.

The core idea

A network is just devices (PCs, phones, printers, cameras) talking to each other by sending data in small pieces called packets. Every device needs an address so others know where to send data — that's an IP address.

Must-know terms

IP Address

A unique numeric address for a device on a network, e.g. 192.168.1.10. Like a home address for your PC.

Subnet Mask

Defines which part of the IP is the "network" and which part is the "device", e.g. 255.255.255.0.

Default Gateway

The router's address — the "door" your device uses to reach other networks/the internet.

DNS

Domain Name System — turns website names (google.com) into IP addresses computers understand.

DHCP

A service (usually on the router) that automatically assigns IP addresses to devices, so you don't set them manually.

MAC Address

A unique physical hardware address burned into a network card. Doesn't change like an IP can.

Router

Connects different networks together (e.g. your home network to the internet). Assigns IPs, routes traffic.

Switch

Connects multiple devices within the same network (e.g. PCs in an office) so they can talk to each other.

Hub

Old, dumb version of a switch — sends data to all ports, not just the right one. Rarely used today, but may be asked about.

Firewall

Software or hardware that blocks unwanted/unsafe traffic in or out of a network.

LAN vs WAN

LAN = Local Area Network (your office/home). WAN = Wide Area Network (the internet, connects LANs together).

PoE

Power over Ethernet — sends electrical power AND data through one ethernet cable. Very important for CCTV cameras and WiFi access points.

Cables & connectors

Cable/Port	Used for
Ethernet (RJ45), Cat5e/Cat6	Wired network connection between PC, switch, router
Coaxial (BNC)	Older analog CCTV cameras and TV signal
Fiber optic	Long-distance, very high-speed network backbone links
USB	Connecting peripherals: mouse, keyboard, external drives
HDMI / VGA / DisplayPort	Connecting a monitor/display to a PC

Common commands (Windows) — practice saying what these do

ipconfig            → shows your PC's IP address, subnet, gateway
ipconfig /all       → shows detailed network info incl. MAC address, DNS
ipconfig /release   → drops current IP address
ipconfig /renew     → requests a new IP address from DHCP
ping 8.8.8.8        → tests if you can reach a device/the internet
ping google.com     → tests connectivity AND DNS at the same time
tracert google.com  → shows every "hop" data takes to reach a destination
nslookup google.com → shows the IP address behind a domain name
netstat -an         → lists active network connections

Interview gold: the "ping test logic"

If asked "user says no internet, what do you do?" — a great instant answer is: "First I'd ping 127.0.0.1 (tests the PC's own network card), then ping the gateway (tests the local network/router), then ping 8.8.8.8 (tests the internet), then ping google.com (tests DNS). Wherever it stops working tells me where the problem is." This single answer impresses interviewers because it shows structured thinking.

Common network ports (just recognize a few)

Port	Service
80	HTTP (websites)
443	HTTPS (secure websites)
21	FTP (file transfer)
22	SSH (secure remote login)
25	SMTP (sending email)
3389	RDP (Windows Remote Desktop)

OSI Model — mention it, don't over-study it

A 7-layer concept of how network communication works. You mainly need to know it exists and name a couple of layers if asked:

7. Application	What the user interacts with (browser, email)
4. Transport	Reliable delivery (TCP/UDP)
3. Network	IP addressing & routing
2. Data Link	MAC addresses, switches
1. Physical	Cables, signals, hardware

If asked "explain OSI model" just say: "It's a 7-layer model describing how data travels from an app on one device to an app on another — from the physical cable up to the software application." That's enough for junior level.

02 Hardware basics

CPU

The "brain" — processes instructions. Brands: Intel, AMD.

RAM

Short-term memory — holds data for programs currently running. More RAM = smoother multitasking. Cleared when PC turns off.

Storage (HDD/SSD)

Long-term storage for files/OS. SSD = fast, no moving parts. HDD = slower, spinning disk, cheaper per GB.

Motherboard

The main circuit board — connects CPU, RAM, storage, and everything else together.

PSU

Power Supply Unit — converts wall power into power the PC's parts can use.

GPU

Graphics card — handles video/graphics rendering. Important for gaming/design PCs.

Cooling (fans/heatsink)

Prevents overheating — CPU has a heatsink+fan, case has airflow fans.

Peripherals

Monitor, keyboard, mouse, printer — external devices connected to the PC.

Quick hardware troubleshooting instinct

PC won't turn on → check power cable, power strip/outlet, PSU switch
No display → check monitor cable, correct input source, try a different port
Random shutdowns → possible overheating (check fans/dust) or failing PSU
Loud beeping on startup → hardware POST error (often RAM not seated properly)
Slow PC → check Task Manager for high CPU/RAM/disk usage, malware, low storage space

03 Software & Operating Systems

Operating System (OS)

The core software that manages hardware and lets you run programs — Windows, macOS, Linux.

Driver

Small software that lets the OS talk to a specific hardware device (e.g. a printer driver, graphics driver).

Device Manager

Windows tool to view/update/troubleshoot hardware and drivers. Yellow warning triangle = driver problem.

Task Manager

Shows running programs, CPU/RAM/disk usage. Used to close frozen apps or spot what's slowing the PC (Ctrl+Shift+Esc).

Control Panel / Settings

Where you manage installed programs, network settings, user accounts, updates.

Event Viewer

Windows tool logging system errors/warnings — used to diagnose crashes or recurring issues.

Remote access tools

AnyDesk, TeamViewer, Windows RDP — let IT support control a user's PC remotely to fix issues.

Antivirus

Software that detects/removes malware — Windows Defender, etc.

Ticketing system

Software IT teams use to track support requests (e.g. Zendesk, Freshdesk) — each user issue = a "ticket" until resolved.

Useful Windows shortcuts to mention

Ctrl + Shift + Esc → open Task Manager
Windows + R        → open Run dialog (type cmd, devmgmt.msc, etc.)
Windows + X        → quick access menu (Device Manager, Disk Management)
Safe Mode          → boot Windows with minimal drivers, for troubleshooting

04 PC troubleshooting method

This is the single most important thing to memorize. It works for almost any "what would you do if..." question.

The golden method (say this in any troubleshooting answer)

Ask/gather info — what exactly happens, when did it start, any recent changes?
Reproduce or verify the problem yourself if possible.
Check the simplest thing first — cables, power, restart. (Most real fixes are this simple.)
Isolate the problem — is it this one PC, or everyone? This app, or all apps? Narrow it down.
Fix it, or escalate to a senior/vendor if beyond your level.
Test that it's actually fixed.
Document what happened and the fix (for the ticket/next time).

Common scenarios — practice answering these

PC won't turn on at all

Check: is it plugged in? Power outlet working (test with another device)? Power strip switched on? PSU switch on back set to "1"? Try a different cable.

PC turns on but no display

Check: monitor powered on and correct input selected? Cable firmly connected at both ends? Try a different cable/port. If still nothing, could be RAM not seated or GPU issue.

"No internet connection"

Run the ping test logic from Section 01: check the WiFi/ethernet is connected, run ipconfig, ping the gateway, ping 8.8.8.8, ping google.com. Also just try restarting the router (unplug 10 sec, plug back in) — fixes a huge percentage of real cases.

PC is very slow

Open Task Manager, check what's using high CPU/RAM/Disk. Check available storage space (low disk space slows PCs a lot). Check for malware. Check for too many startup programs.

Printer not working

Check it's powered on and connected (USB/network). Check for paper jams / paper / ink. Check it's set as default printer. Try restarting the "Print Spooler" service or restarting the printer.

User forgot their password

Verify their identity first (security!), then reset password through Active Directory/user management tool, and set "must change password at next login".

Escalation — a key phrase interviewers want to hear

"If I've checked the basics and I'm not sure how to fix it, I'd escalate to a senior technician or vendor support rather than guess — but I'd document exactly what I already tried so they don't repeat steps."

05 CCTV setup & management

Analog camera

Older type, connects via coaxial (BNC) cable to a DVR (Digital Video Recorder). Needs a separate power cable.

IP camera

Modern type, connects via ethernet cable to an NVR (Network Video Recorder) or network switch. Usually gets power AND data via one PoE cable.

DVR

Records footage from analog cameras. Footage stored on internal hard drive.

NVR

Records footage from IP cameras over the network. More flexible, better quality typically.

PoE Switch

A network switch that supplies power to connected devices (cameras) through the same ethernet cable — no separate power adapter needed per camera.

Remote viewing app

Mobile/PC apps (e.g. Hik-Connect, CamHi) let you view cameras remotely once DVR/NVR is connected to the internet.

Basic install process (typical junior task)

Plan camera positions — entrances, blind spots, height ~2.5–3m to avoid tampering, avoid pointing directly at sun/lights.
Run cabling — ethernet (for IP/PoE) or coaxial + power (for analog) from each camera location back to the DVR/NVR/switch.
Mount the camera bracket securely, connect cable.
Connect to DVR/NVR — IP cameras usually auto-detect on the NVR; analog cameras just need the coax + power connected.
Configure recording settings — continuous recording vs motion-detection only, storage retention period (e.g. keep 30 days).
Set up remote access — connect NVR/DVR to internet/router, register on the manufacturer's app, scan QR code / enter serial to link.
Test each camera's live view and playback, adjust angle/focus as needed.

Common CCTV troubleshooting

No video from one camera → check cable connection, try a different port on the NVR/switch, check camera has power (PoE)
Blurry/dark image → clean the lens, adjust focus ring, check for night-vision (IR) mode setting
Can't view remotely → check internet connection at the site, check port forwarding/cloud service status, re-check app login
No recordings saved → check hard drive isn't full/failed, check recording schedule settings
Camera keeps disconnecting → check cable quality/length limits (ethernet max ~100m without extenders), check PoE switch isn't overloaded

06 Interview Q&A — practice out loud

Read each question, cover the answer, try to answer yourself first, then check.

Tell me about yourself / why IT support?

Keep it short: your background, why you're interested in IT, and one honest note that you're early in your career but eager to learn and reliable. YOU COULD SAYI'm just starting my career in IT. I've been learning networking and troubleshooting fundamentals, and I'm someone who stays calm under pressure and likes solving problems step by step. I'm looking for a junior role where I can learn hands-on and grow into a strong technician.

What is an IP address / what is DNS / what is DHCP?

Use the simple definitions from Section 01. Keep answers to 1–2 sentences — don't over-explain.

A user says "the internet is not working" — walk me through what you'd do.

Use the golden troubleshooting method + ping test logic (Sections 01 & 04). This is one of the most commonly asked questions.

Difference between a router and a switch?

YOU COULD SAYA switch connects multiple devices within the same local network so they can talk to each other. A router connects different networks together — like connecting your local network to the internet — and assigns IP addresses.

Have you set up a CCTV system before?

If you haven't, be honest but show you understand the concept. YOU COULD SAYI haven't installed one professionally yet, but I understand the basics — IP cameras connect via PoE ethernet to an NVR, analog cameras connect via coax to a DVR, and you configure recording and remote viewing through an app. I'm confident I can learn the specific hardware quickly with guidance.

How do you handle a problem you don't know how to fix?

YOU COULD SAYI'd try to isolate the issue with basic troubleshooting first, search documentation or reliable sources, and if I'm still stuck, I'd escalate to a senior colleague rather than guess — while documenting what I already tried.

How do you handle an angry or frustrated user?

YOU COULD SAYI stay calm, listen fully before responding, acknowledge their frustration, and focus on solving the problem rather than getting defensive. Most frustration comes from feeling unheard, so listening first goes a long way.

Do you prefer working alone or in a team?

Give a balanced answer — IT support usually needs both independent troubleshooting and teamwork with colleagues/vendors.

Why should we hire you with no experience?

YOU COULD SAYI understand this is an entry-level role and I don't expect to know everything on day one. What I bring is a strong willingness to learn quickly, a calm and methodical approach to problems, and reliability — I show up, ask good questions, and follow through.

Do you have any questions for us?

Always ask something — it shows interest. Good options: "What does a typical day look like in this role?"
"What tools or ticketing system does the team use?"
"Is there training provided for someone new to CCTV/networking specifically?"

07 Practice quiz

Answer each question. Click an option to see if you're right, then move to the next.

Question 1 / 0 · Score: 0