2026-09-20 · help-desk, tcm, class-notes
The Practical Help Desk course takes someone with no IT experience to the point where they can do the real work of a Tier 1 help desk technician. It's also the foundation TCM recommends before its more advanced…
Class notes · TCM Security, Practical Help Desk · Section 1
Quick reference: the short version of this section is the Section 1 cheat sheet.
By the end of these notes you should be able to:
The Practical Help Desk course takes someone with no IT experience to the point where they can do the real work of a Tier 1 help desk technician. It's also the foundation TCM recommends before its more advanced security courses.
The sections build in a deliberate order: first you learn how computers work, then how to fix them, then how to run and support them at scale.
Foundations Hardware Systems Support at scale
1 Introduction --> 4 Desktops --> 6 Operating --> Networking 2 Intro to IT 5 Laptops systems Security basics 3 Intro to 7 Virtualization Remote support computing Windows & Linux Ticketing admin Active Directory capstone
Stage
Why it comes here
Intro to IT and computing
You can't troubleshoot what you don't understand. Binary, encoding and how a CPU works explain why things fail
Desktop and laptop hardware
A large share of real tickets are physical: dead batteries, failing drives, loose cables
Operating systems and virtualization
Most problems live in the OS. Virtualization gives you a safe place to break and fix them
Networking, security, remote support
Modern help desks fix most issues remotely, over the network, without leaving their desk
Ticketing and Active Directory
This is the day job: tickets arrive, and most involve user accounts in a directory
Tier 3 Engineers / specialists (architecture, complex fixes) ^ Tier 2 Desktop support / sysadmin (deeper technical problems) ^ Tier 1 Help desk <-- this course: first contact, triage, common fixes ^ Tier 0 Self-service (knowledge base, password-reset portals)
Tier 1 is the entry point for most IT careers. From there, common paths lead to:
In the real world: hiring managers for junior SOC roles often prefer candidates with help desk experience over those with certifications alone. Knowing how a real organisation's machines, accounts and users behave is hard to learn any other way.
Format
What it is
How to get the most from it
Video lessons
Concept explanations and demonstrations
Pause and repeat demonstrations yourself; don't just watch
Hands-on labs
You perform the task in your own lab
Do every lab. This is where the learning actually happens
Ticket Interrupts
A realistic support ticket arrives mid-course
Treat it like a real job: read carefully, form a theory, test it, write up the fix
Check-in quizzes
Short tests at the end of each section
Take them before re-watching anything — the gaps they reveal are what to revise
The course lines up with TCM Security's PHDA (Practical Help Desk Associate) certification. TCM positions it as the first step on its Security Operations path. TCM's certifications emphasise practical, hands-on assessment. Check the current exam format and requirements on TCM's site before you book, as details can change.
A lab is a set of computers you're allowed to break. For this course it will be virtual machines (VMs) running on your own PC. Virtualization gets its own section later; here's what you need to get started.
Resource
Minimum
Comfortable
Why
RAM
8 GB
16 GB or more
Every running VM needs its own slice of memory
Free disk
80 GB
100 GB or more
Each Windows VM wants 40–60 GB
Disk type
—
SSD
VMs on a hard drive are painfully slow
CPU
4 cores
6 cores or more
Several VMs run at once
Virtualization
Must be enabled
—
Without it, VMs won't start or run very slowly
A hypervisor is the software that creates and runs virtual machines.
Type
Runs on
Examples
Good for
Type 2 (hosted)
Your normal OS, like any app
VirtualBox (free), VMware Workstation
Learning on your everyday PC — the usual choice for this course
Type 1 (bare metal)
Directly on the hardware
Proxmox VE, VMware ESXi, Hyper-V
A dedicated lab machine or server
Exam tip: Type 1 = bare metal (no host OS underneath). Type 2 = hosted (runs on top of an OS). Hyper-V counts as Type 1, even though you switch it on from inside Windows.
Modern CPUs include hardware virtualization extensions, but they're often switched off in the firmware:
How to check (Windows):
systeminfo | findstr /i "Virtualization" (Get-CimInstance Win32_Processor).VirtualizationFirmwareEnabled
How to check (Linux):
grep -Ec '(vmx|svm)' /proc/cpuinfo \
How to enable it:
Note: if Hyper-V, WSL 2 or Windows' Virtual Machine Platform is enabled, Windows itself runs on a hypervisor. systeminfo then reports that a hypervisor has been detected rather than showing the firmware setting. Most desktop hypervisors can run alongside it, sometimes with a performance cost.
Goal: a small Windows domain plus a Linux box, all running at once.
Machine
RAM
Disk
Role
Windows Server
4 GB
60 GB
Domain controller (the Active Directory capstone)
Windows 11
4 GB
60 GB
A "user" workstation to support
Ubuntu
2 GB
25 GB
Linux administration practice
Total for VMs
10 GB
145 GB
Left for the host
6 GB
—
Enough for Windows plus a browser
Reasoning:
OS
Source
Notes
Windows 11 Enterprise
Microsoft Evaluation Center
90-day evaluation
Windows Server
Microsoft Evaluation Center
180-day evaluation
Ubuntu
ubuntu.com
Free; choose the LTS release
Only download images from the official source (see the security section).
This is the most important lab decision for safety.
Mode (VirtualBox names)
VM can reach internet?
VMs see each other?
Visible on your home network?
Use for
NAT
Yes
No
No
A single VM that just needs internet
NAT Network
Yes
Yes
No
Default for this course — a private lab that can still update
Host-only
No
Yes (and the host)
No
Fully offline labs
Internal
No
Yes (not the host)
No
Isolated VM-only networks
Bridged
Yes
Yes
Yes
Only when a VM must act like a real device on your LAN
Internet | [Home router] ---- your phone, TV, other PCs <- bridged VMs appear HERE | [Host PC] | (virtual NAT router) <- NAT Network lives HERE | | | [Server] [Win 11] [Ubuntu]
A snapshot saves a VM's complete state so you can roll back instantly.
In the real world: a snapshot is not a backup. It depends on the original disk file — if that's corrupted or deleted, the snapshot goes with it.
Technique
What you do
Why it works
Active recall
Close the notes and answer questions from memory
Retrieving information strengthens memory far more than re-reading
Spaced repetition
Review after 1 day, 3 days, 1 week, 1 month
Memory decays predictably; timed reviews catch it just before you forget
Doing, not watching
Complete every lab yourself
Skills live in your hands, not in the video
Explain it simply (Feynman technique)
Teach the idea in plain words, as if to a beginner
Gaps in understanding show up immediately
Interleaving
Mix topics in one study session
Builds the ability to pick the right tool for a problem
Layer
Purpose
Example
Class notes (like these)
Full understanding, read once or twice
Why RAID 5 survives one drive failure
Cheat sheet
Fast lookup during work
RAID 5: min 3 disks, survives 1
Lab log
What you did, what broke, how you fixed it
"VT-x disabled in BIOS; enabled under Advanced → CPU"
The lab log is the most underrated. It becomes your personal troubleshooting database, and great interview material ("tell me about a problem you solved").
Asking a good question is the same skill as writing a good ticket or escalation.
Element
Bad
Good
Goal
"It doesn't work"
"I'm trying to install Ubuntu in VirtualBox for the Linux lab"
Symptom
"Error"
"The VM fails to start: VT-x is not available (VERR_VMX_NO_VMX)"
Already tried
—
"Enabled virtualization in BIOS, rebooted, turned off Hyper-V"
Environment
—
"Windows 11 host, 16 GB RAM, VirtualBox 7"
Before:
"my vm is broken pls help"
After:
"Goal: run the Windows 11 VM for the section 6 lab. Problem: it boots to a black screen, then shows No bootable medium found. Tried: checked the ISO is attached in Settings → Storage — it wasn't; I attached it and got the same result. Environment: VirtualBox 7 on Windows 11, VM set to EFI. Question: is the boot order wrong, or is this an EFI/ISO mismatch?"The second version can be answered in one reply. The first needs a round of questions just to find out what's wrong.
Habit
What it looks like
Question the obvious
Is it plugged in? Is the right account signed in? Has it been restarted?
Reproduce first
See the problem yourself before changing anything
Change one thing at a time
Otherwise you won't know what fixed it
Document as you go
Your ticket notes are your memory, and your colleague's hand-over
Own the ticket
Keep the user updated until the issue is closed, even if you escalated it
Be kind
Users are often stressed; a calm tone solves half the problem
These habits are practised in each Ticket Interrupt. Treat every one as a real user waiting on you.
Get-FileHash .\ubuntu-24.04-desktop-amd64.iso -Algorithm SHA256 sha256sum ubuntu-24.04-desktop-amd64.iso- - A mismatch means a corrupted or tampered file — don't use it.
Term
Definition
Help desk / service desk
The first point of contact for IT problems and requests
Tier 1
Front-line support: logging, triage, common fixes, escalation
Home lab
Your own set of machines, usually virtual, for safe practice
Virtual machine (VM)
A complete computer simulated in software
Hypervisor
Software that creates and runs virtual machines
Type 1 hypervisor
Runs directly on hardware (bare metal)
Type 2 hypervisor
Runs as an application on a host operating system
Host / guest
The physical machine / the virtual machine running on it
VT-x / AMD-V
Intel / AMD hardware virtualization extensions
ISO
A disk image file, used to install an operating system
Snapshot
A saved point-in-time state of a VM you can revert to
NAT Network
A private virtual network whose VMs can reach the internet but aren't reachable from your LAN
Bridged networking
The VM joins your physical network as if it were a real device
Thin provisioning
A virtual disk that grows only as data is written
SHA-256 hash
A fingerprint of a file, used to confirm it hasn't been altered
Active recall
Studying by retrieving information from memory rather than re-reading