How to Diagnose and Fix Common IT Issues Like a Pro

Technology is brilliant until it isn't. The good news is you don't need to be an IT expert to fix most everyday problems. With a calm, step-by-step approach, you can sort out a surprising amount yourself.

Here are the problems I see most often, and the checklists I'd work through for each one.

1. Slow internet

1. Check if it's every device or just one. If it's only one, the problem is that device, not your broadband.
2. Run a speed test, ideally on a device plugged in with a cable, so you know whether the problem is your Wi-Fi or the line itself.
3. Restart the router. Turn it off, wait 30 seconds, and turn it back on.
4. Move closer, or move the router. Wi-Fi hates thick walls, cupboards and being stuck behind the TV.
5. Check what's hogging the connection. Big downloads, game updates and cloud backups can slow things down for everyone.
6. Change the Wi-Fi channel if lots of neighbours' networks are nearby. Many routers can pick the best one automatically.

If it's still slow when plugged in with a cable, contact your broadband provider. There may be a fault on the line.

2. Computer won't start

1. Check the power. Is the plug switched on, the cable pushed in fully and the laptop charger's light on?
2. Look and listen. Do any lights, fans or beeps happen? Beep codes and blinking lights point to specific hardware problems, so look them up for your model.
3. Unplug everything else (USB drives, docks, printers) and try again.
4. If Windows starts but crashes, try Safe Mode. Hold Shift while clicking Restart, then go to Troubleshoot > Advanced options > Startup Settings.
5. Use built-in diagnostics. Many laptops and PCs have hardware tests you can run at startup (often F12 or F2, depending on the maker).

If the drive is clicking or the PC still won't start, stop and get help, especially if there are files on it you haven't backed up.

3. Software updates failing

1. Check your connection is stable, and plug in a laptop's charger.
2. Free up space. Updates need room to unpack, so I'd keep at least 10 to 15 per cent of the drive free.
3. Restart and try again. It fixes more than you'd think.
4. On Windows, run the troubleshooter in Settings > System > Troubleshoot > Other troubleshooters > Windows Update.
5. If an update causes problems, you can uninstall it from Settings > Windows Update > Update history > Uninstall updates.
6. Repair system files from a Command Prompt opened as administrator:

DISM /Online /Cleanup-Image /RestoreHealth
sfc /scannow

4. Printer not responding

1. Check the basics: power, paper, ink or toner, and any error lights.
2. Turn the printer off and on, and restart the computer.
3. Check it's on the same network. Wi-Fi printers often drop off after the router has been restarted or changed.
4. Clear the print queue. A single stuck job can block everything behind it.
5. Install the latest driver from the manufacturer's website.
6. Run the printer troubleshooter built into Windows or macOS.

5. Apps crashing

1. Update the app and your operating system.
2. Close other apps to free up memory.
3. Check it supports your system. Older apps may not work on newer systems.
4. Clear the app's cache or temporary files.
5. Uninstall and reinstall it to replace any damaged files.

6. Preventing and recovering lost files

If you've just deleted something:

• Check the Recycle Bin (Windows) or Bin (Mac) first.
• Check your cloud storage's own bin. OneDrive, Google Drive and iCloud keep deleted files for a while.
• For a deleted file on a traditional hard drive or USB stick, a recovery tool like Recuva or Microsoft's free Windows File Recovery may get it back. Stop using the drive straight away so nothing overwrites it.
• On modern SSDs, deleted files are usually wiped quite quickly, so recovery is much less likely. That's why backups matter so much.

To stop it happening again:

• Follow the 3-2-1 rule: three copies of important files, on two different types of storage, with one kept off-site (cloud storage counts).
• Set backups to run automatically. Backups you have to remember don't happen.
• If a drive starts clicking, grinding or getting very slow, back it up straight away.

For really important data on a failed drive, professional recovery services exist, but they aren't cheap.

7. Firewall and security settings

1. Keep the built-in firewall switched on. If it's blocking an app you need, allow that one app rather than turning the firewall off.
2. Run a full malware scan. Microsoft Defender, built into Windows, is good enough for most people.
3. Keep everything updated: operating system, browser and apps.
4. Turn on real-time protection and leave it on.
5. Use two-factor authentication on your email and important accounts.

If you think you've been hacked or scammed, change your passwords from a different, clean device. In England, Wales and Northern Ireland you can report fraud and cybercrime to Report Fraud (it replaced Action Fraud in December 2025). In Scotland, call Police Scotland on 101.

Final thoughts

Most IT problems can be solved by working through the checklist calmly, one step at a time. Spotting the symptoms, trying the simple fixes first and knowing when to call in help will save you time, money and stress. And if you do one thing after reading this, set up automatic backups.