> ## Documentation Index
> Fetch the complete documentation index at: https://docs.derekdinh.com/llms.txt
> Use this file to discover all available pages before exploring further.

# IT Troubleshooting Knowledge Base: Your IT Support Hub

> A central IT support hub covering networking, Windows, macOS, Linux, hardware, security, and cloud/SaaS for helpdesk teams, sysadmins, and power users.

This knowledge base is your centralised reference for diagnosing and resolving common IT issues quickly and confidently. Whether you are responding to a helpdesk ticket, maintaining infrastructure, or troubleshooting your own workstation, the guides here walk you through proven, systematic approaches that reduce downtime and eliminate guesswork. Every article follows a consistent structure — from identifying symptoms to applying fixes and knowing when to escalate — so you spend less time searching and more time solving.

## Who This Knowledge Base Is For

This resource is designed for anyone who supports, administers, or relies on modern IT systems:

* **Helpdesk & IT Support Staff** — First-line agents handling tickets need fast, reliable steps to resolve common issues without escalating unnecessarily.
* **System Administrators** — Sysadmins managing servers, networks, and endpoints will find in-depth diagnostic procedures and configuration references.
* **IT Managers & Team Leads** — Use these guides to build runbooks, onboard new staff, and standardise your team's troubleshooting processes.
* **Power Users & Self-Service** — Technical users who prefer to resolve issues independently before raising a ticket will find clear, step-by-step guidance.

## Why Systematic Troubleshooting Matters

Ad-hoc troubleshooting — trying random fixes until something works — wastes time, risks making problems worse, and rarely produces lasting results. A systematic approach means you gather information first, form a hypothesis, test one change at a time, and document the outcome. This knowledge base is built around that methodology. Every guide starts with symptoms, moves through diagnostics, and only then recommends targeted fixes. Following this pattern consistently leads to faster resolution times and fewer repeat incidents.

<Note>
  If you are new to this knowledge base, start with the [How to Use](/how-to-use) guide to understand how articles are structured and how to get the most out of each section.
</Note>

## Knowledge Base Sections

Browse the main topic areas below. Each section groups related guides so you can quickly navigate to the technology or problem type you are dealing with.

<CardGroup cols={2}>
  <Card title="Networking & Connectivity" icon="network-wired" href="/networking">
    Diagnose and fix LAN, Wi-Fi, VPN, DNS, DHCP, and internet connectivity issues across corporate and remote environments.
  </Card>

  <Card title="Windows Troubleshooting" icon="windows" href="/windows">
    Resolve boot failures, update errors, driver conflicts, performance degradation, and Group Policy problems on Windows 10 and 11.
  </Card>

  <Card title="macOS & Linux" icon="apple" href="/unix/macos-startup-issues">
    Address system crashes, permission errors, package management issues, and shell scripting problems on macOS and common Linux distributions.
  </Card>

  <Card title="Hardware & Peripherals" icon="microchip" href="/hardware">
    Troubleshoot unrecognised devices, display faults, storage failures, printer issues, and overheating across desktops and laptops.
  </Card>

  <Card title="Security & Access" icon="shield-halved" href="/security">
    Handle account lockouts, MFA failures, certificate errors, endpoint protection alerts, and suspected security incidents.
  </Card>

  <Card title="Cloud & SaaS" icon="cloud" href="/cloud/microsoft-365-issues">
    Resolve authentication failures, sync errors, and configuration issues across Microsoft 365, Google Workspace, and other cloud platforms.
  </Card>
</CardGroup>

## Foundational Troubleshooting Principles

Every guide in this knowledge base is grounded in the following principles. Keeping them in mind as you work through any issue will make you a more effective troubleshooter regardless of the technology involved.

<AccordionGroup>
  <Accordion title="Define the problem before touching anything">
    Before running a single command or changing a setting, clearly articulate what is broken, when it started, what changed recently, and who is affected. A well-defined problem is already half solved. Skipping this step is the single most common cause of extended troubleshooting sessions.
  </Accordion>

  <Accordion title="Change one thing at a time">
    Applying multiple fixes simultaneously makes it impossible to know which change resolved the issue — or which one caused a new one. Always test after each individual change and document the result before proceeding.
  </Accordion>

  <Accordion title="Reproduce before you resolve">
    If you cannot reliably reproduce the problem, you cannot confirm your fix worked. Establish a repeatable test case early, even if it is as simple as a sequence of clicks or a single command that triggers the error.
  </Accordion>

  <Accordion title="Document as you go">
    Record every step you take, every command you run, and every result you observe — even dead ends. This log is invaluable if you need to hand the case to another engineer, raise a vendor support ticket, or write a post-incident review.
  </Accordion>

  <Accordion title="Know when to escalate">
    Systematic troubleshooting includes recognising the limits of your own access and expertise. Each guide in this knowledge base includes an escalation path that tells you when to involve a specialist, raise a P1 ticket, or contact a vendor.
  </Accordion>
</AccordionGroup>

## Contributing to This Knowledge Base

This resource grows with the experience of the whole team. If you resolve an issue that is not yet documented here, or if you find a guide that needs updating, please see the [Contributing](/contributing) page for instructions on how to submit a new article or improvement.

<Tip>
  Bookmark this introduction page as your starting point. The search bar at the top of every page is the fastest way to find a guide — search by error message, symptom, or technology name.
</Tip>