Basic Troubleshooting

Introduction

Something is wrong with your computer. Maybe it will not turn on. Maybe it is painfully slow. Maybe the internet is not working. Maybe an application keeps crashing. Whatever the problem, your first instinct might be to panic or immediately call someone for help. But most computer problems have simple solutions, and developing basic troubleshooting skills saves you time, money, and frustration.

Troubleshooting is the systematic process of identifying, diagnosing, and resolving problems. The key word is systematic — good troubleshooting is not random guessing. It follows a logical process of elimination, starting with the most likely and simplest causes before moving to more complex ones. This chapter teaches you that process and applies it to the most common computer problems you will encounter.

The Universal Troubleshooting Process

Before diving into specific problems, learn the general approach that applies to any technical issue.

Step 1 — Identify the problem clearly. What exactly is wrong? When did it start? What changed recently? Was new software installed? Was hardware added or removed? Getting precise about the symptom is half the battle.

Step 2 — Reproduce the problem. Can you make it happen consistently? If a program crashes, does it crash every time or only sometimes? Understanding when the problem occurs helps narrow the cause.

Step 3 — Start with the simplest explanation. The most common fix in all of IT support is "turn it off and turn it back on again" — and it works shockingly often because it clears temporary states and reloads everything fresh. Always try the simplest solution first.

Step 4 — Change one thing at a time. If you change three things simultaneously and the problem goes away, you do not know which change fixed it. Modify one variable, test, then modify the next if needed.

Step 5 — Document what you tried. Keep a mental or written note of what you have already attempted so you do not repeat steps and can communicate clearly if you need to escalate to someone else.

Computer Will Not Turn On

This is one of the most alarming problems because you cannot even begin to use the machine. Work through these checks in order.

First, check the obvious — is it plugged in? Is the power strip turned on? Is the wall outlet working (test with another device)? For laptops, is the battery completely dead? Connect the charger and wait a few minutes before trying again.

If there is no response at all (no lights, no fan noise), the power supply might have failed, or the power cable might be damaged. Try a different cable if available. For desktops, check that the power switch on the back of the power supply is in the ON position.

If you hear fans spinning but see nothing on screen, the problem might be the display connection. Check that the monitor is on and connected to the correct port. Try a different cable or port. For laptops, try connecting an external monitor to determine if the built-in display has failed.

If the computer starts but immediately turns off, it might be overheating (check if ventilation is blocked by dust or objects) or a hardware component might be failing.

Computer Is Running Slowly

Slow performance is the most common complaint and has many possible causes. Work through these diagnostically.

Check what is using resources. Open Task Manager (Ctrl+Shift+Esc on Windows) or Activity Monitor (on Mac) and look at CPU and memory usage. If a specific application is using 90% of your CPU, you have found your culprit — close it or investigate why it is misbehaving.

Insufficient RAM causes slowness because the computer must constantly swap data between RAM and the much slower hard drive. If memory usage is consistently above 85-90%, consider closing unnecessary applications or upgrading RAM. Too many browser tabs is a common cause — each tab uses memory.

A nearly full hard drive causes slowness because the operating system needs free space for virtual memory and temporary files. If your drive is more than 90% full, delete unnecessary files or move them to external storage. Empty the Recycle Bin, clear temporary files (Disk Cleanup on Windows), and uninstall programs you no longer use.

Malware (viruses, spyware) can consume resources in the background. Run a full antivirus scan. If you do not have antivirus software, Windows Defender (built into Windows) provides basic protection.

Startup programs are a hidden cause of slowness. Many programs add themselves to startup, running whenever your computer boots even if you do not need them. Open Task Manager, click the Startup tab, and disable programs you do not need running immediately at boot.

If the computer is old and has a traditional hard drive (HDD), upgrading to a solid-state drive (SSD) provides the single biggest performance improvement — often making the computer feel like new.

Internet Not Working

Internet connectivity problems are extremely common. The troubleshooting process starts at your device and works outward.

First, check if the problem is your device or the network. Can other devices connect? If other devices work fine, the problem is specific to your device. If nothing can connect, the problem is likely your router or ISP.

Restart the router. Unplug it, wait 30 seconds, and plug it back in. Wait 2-3 minutes for it to fully restart and reconnect. This resolves a surprising majority of home internet issues.

On your device, try disabling and re-enabling WiFi. On Windows, run the Network Troubleshooter (Settings then Network then Network troubleshooter). Check if airplane mode is accidentally enabled.

If you can connect to the router but cannot reach websites, try pinging an IP address directly — if ping works but websites do not load, the DNS might be the issue. Try changing your DNS to 8.8.8.8 (Google DNS) or 1.1.1.1 (Cloudflare DNS).

If only specific websites are not working, the problem might be on their end, not yours. Check isitdown.com or try accessing the site from your phone using cellular data (not WiFi) to confirm.

Application Crashes

When a program crashes, freezes, or produces errors, try these steps. Close and reopen the application — the most basic fix. If it is frozen (not responding), force-close it through Task Manager. Update the application — bugs in older versions might be fixed in newer ones.

Restart your computer — this clears any temporary state conflicts between programs. Check for operating system updates — compatibility issues sometimes arise between apps and older OS versions.

If the application worked before and suddenly stopped, think about what changed. Was a Windows update installed? Was another program installed that might conflict? Uninstalling recent changes might resolve the issue.

As a last resort for persistent application problems, uninstall and reinstall the application. This gives you a fresh copy of all program files, replacing any that might have been corrupted.

Key Takeaways

• Troubleshooting is systematic, not random — follow a logical process of elimination
• "Turn it off and on again" genuinely fixes a surprising number of problems
• Task Manager is your best friend for diagnosing performance issues
• Always start with the simplest, most likely cause before investigating complex possibilities
• Check cables, power, and connections before assuming component failure
• For internet issues, restart the router first and check if other devices have the same problem
• Keep your system updated, drives not overly full, and startup programs minimal for best performance
• Document your troubleshooting steps — this helps if you need to escalate to professional support