Here at Computer Repair Adelaide, we’ve been helping people with their computers for over 10 years. In that time, we’ve seen how quickly small slips can lead to big security problems. It’s easy to think, “That won’t happen to me,” or simply forget basic steps.
These security mistakes can cause big issues. They can lead to lost files, frozen computers, or even identity theft.
So, here, we will explain five of the biggest security mistakes we see every day. We will also give you simple, actionable ways to protect your PC and keep your digital life safe.
Connecting to public wifi
You are probably familiar with this. You are at your local café, you see “Free Wi-Fi,” and you connect quickly to check your bank balance or send an important work email. Most people do this without thinking twice about how safe their connection is.
The Risk of Free Wi-Fi
We often have clients report strange activity on their accounts or even getting viruses after using public Wi-Fi. The unfortunate truth is that public Wi-Fi networks are easy targets for cybercriminals. They can set up fake networks or use weaknesses in real ones to steal your information as it travels over the internet.
Trend data from 2024 shows this risk is growing. Data breaches linked to public Wi-Fi use increased by 15% in 2024 due to new attack methods. These problems often lead to expensive computer clean-ups and, sometimes, identity theft.
Simple Ways to Stay Safe
- Use a VPN: This is the most important step for public Wi-Fi. A VPN (Virtual Private Network) encrypts your internet connection. This makes your data unreadable to anyone trying to snoop on the network.
- Limit Sensitive Tasks: Avoid online banking, shopping, or sending important work emails when connected to public Wi-Fi. Save these tasks for when you are on a secure home or work network.
- Use Your Phone’s Hotspot: Your phone’s mobile data connection is usually much more secure than public Wi-Fi. If you need to work on the go, using your phone as a personal hotspot offers better protection.
Leaving Computer and Laptop Unattended
Your home computer or laptop might sit on your desk, and anyone can turn it on and get to your files because there is no password. You might think, “No one will touch it!”
But even at home or in an office, an unlocked computer is a significant risk.
The Danger of an Unattended Devices
We have often helped clients whose personal information was accessed by others. Some computers were even changed by someone who should not have touched them. Even a quick look can cause serious privacy issues or accidentally damage your important files. These breaches often mean expensive repairs, data recovery, and loss of trust.
Simple Ways to Lock It Down
- Always Use a Strong Password or PIN: Every device needs a password. This is the most basic step. Make sure your password or PIN is strong and unique to each computer.
- Use Biometrics: Fingerprint or face login, like Windows Hello, offers both convenience and strong security. It is much faster than typing a password every time.
- Lock Your Screen: Get into the habit of locking your computer when you walk away, even if it is just for a minute. The fastest way to do this in Windows is to press Windows Key + L.
- Encrypt Your Drives (A Pro Tip): For the highest level of security, especially if your laptop could be lost or stolen, consider full disk encryption. Windows Pro versions have BitLocker built-in. This scrambles all the data on your drive, making it unreadable to anyone without the password. It is a more advanced step, but very effective.
Using Same Password Everywhere and Everytime
You use a username and password for almost everything online: your banking, email, and social media. You probably think your passwords are strong and unique.
But then you hear about another big company data breach, and suddenly your email is on a list of stolen passwords. Even a very strong password can be stolen in these attacks.
Why Passwords Alone Aren’t Enough
This is a huge problem we see regularly. Clients come to us upset because their email was hacked, bank accounts were emptied, or social media was taken over. We spend hours helping them get their accounts back.
The problem is clear. In 2024-2025, 80% of all data breaches happened because of stolen login details. That statistic shows that relying on a single password, no matter how strong, is a massive risk.
Adding a Second Layer of Security (MFA)
Multi-Factor Authentication (MFA) is the simplest and most effective way to protect your accounts. Think of it as a second lock on your digital door.
Even if someone steals your password, they still need that second thing to get in. This second factor is usually:
- A code sent to your phone.
- A fingerprint scan.
- A notification on an app like Google Authenticator.
MFA stops over 99.9% of automated attacks, which means it provides incredibly strong protection. It is easy to turn on for almost all important online accounts, including your email, banking, and social media. It is the best defence you have against stolen passwords.
Risky Downloads and Plugging in Unknown USB Drives
A friend gives you a USB drive with some photos. You plug it into your computer. Or, you download a “free” video converter from a website you found in a search. Everything seems fine, but soon after, your computer starts acting strangely.
This is a common and dangerous mistake.
The High Cost of “Free” Software
Plugging in unknown USB drives or downloading software from unofficial sources is a very common way to get serious computer viruses. We often see clients bring us computers infected with Trojans, ransomware, or stubborn viruses that require deep cleaning or even full system resets. This can quickly turn “free” software into a very expensive lesson.
Safe Downloading Habits
- Scan External Drives: Always scan any USB drive or external storage you do not recognise with your antivirus software before opening any files. If you do not have another antivirus, Windows Defender is built into Windows and can do this for you.
- Official Sources Only: Only download software from official websites, trusted app stores (like the Microsoft Store), or reliable, well-known distributors. Avoid clicking on “download” links from pop-up adverts or unfamiliar websites.
- Use Good, Updated Antivirus: Make sure your antivirus software, whether it is Windows Defender or a third-party programme, is always running in the background and is kept fully up-to-date.
Skipping Software Updates
It’s easy to ignore those update notifications. You might have an older Windows 10 computer that still works fine, or you skip system updates because you think, “It is still working just fine!”
But ignoring updates, especially for your operating system and important software, is a big security risk.
The Danger of Outdated Software
When an operating system gets older and no longer receives updates, like Windows 10 is nearing its end in October 2025, it stops getting important security fixes. This leaves your computer open to new threats. We then see clients whose computers are easily hacked or infected by new viruses that could have been prevented.
Fact: Operating systems past their end-of-life are 5 times more likely to be attacked because of known weaknesses. Beyond security, old software also struggles to run new programmes and hardware correctly.
Why You Must Update
Updating isn’t just about getting new features. It’s about protecting your computer.
- Prioritise OS Upgrades: Upgrade to the latest operating system when you can. For those still on Windows 10, now is the time to plan your move.
- Enable Automatic Updates: Make sure automatic updates are turned on for Windows and all other important software like your web browser and antivirus. This ensures you always have the latest security protection.
- Plan for End-of-Life: Know when your operating system or major software programmes will stop getting updates. Plan to upgrade or replace your computer before it becomes a major security risk.
Your Local Tech Partner for a Safer Online Life
These pc security mistakes are not just big tech terms. They are real reasons people in Adelaide come to us, facing lost data, hacked accounts, and frustrating computer problems.
You do not have to wait for a security problem to happen. By following these simple, strong tips, you can greatly reduce your risk. This helps keep your computer running well and safely.
If you have already made a mistake, or you are not sure about your computer’s security, do not worry! Our team of local Adelaide computer experts is here to help. We offer virus removal, data recovery, security setup, and personal advice.
Give Computer Repair Adelaide a call today to chat about your security needs.
FAQs on PC Security Mistakes
Stolen login details are the biggest risk, often due to data breaches. This is why Multi-Factor Authentication (MFA) is so important.
First, check that Windows and your antivirus are updated. Ensure your PC has a password. Scan external drives and review browser security settings.
Common issues include stolen passwords, unsafe public Wi-Fi use, malware from risky downloads, and outdated software.
Use strong passwords with MFA. Only download from trusted sources. Keep all software updated. Use a VPN on public Wi-Fi. Always lock your PC
