Is it my computer or my internet? How to tell in two minutes

If we sent you this link, start with the two-minute test below, then follow the link it points you to. You do not need to install anything.

A slow computer and a slow internet connection feel exactly the same from the chair: you click, and you wait. We often hear “the internet is slow” when the internet is fine and the computer is the problem, and the other way round. Two minutes with your phone tells you which, so you fix the right thing, and if you would rather someone did it with you, home tech support that checks the computer and the connection in one visit is what we do.

Is it my computer or my internet? The two-minute test

Compare the computer with another device on the same WiFi. If the other device is quick and the computer is slow, it is the computer. If everything is slow, it is the connection. Here is the test, in order:

1. 1

   Pick up your phone

   Make sure it is on your home WiFi, not mobile data, and stand in the same room as the computer. Open the same website on both.

2. 2

   Run a speed test on each

   Use the same speed test on the phone, then on the computer, one after the other. Two similar numbers mean the connection is the same for both.

3. 3

   Try a different website

   If only one website is slow and every other site is quick, the problem is that website, not your computer or your internet.

4. 4

   Open something that is already on the computer

   Open a photo or a document saved on the computer itself, and a program you use every day. None of that needs the internet. If that is slow too, it is the computer.

Check your speed first Run it on your phone, then on the computer, in the same room on the same WiFi. If the phone is quick and the computer is slow, it is the computer.

Tap what you're seeing

Slow on every website Slow on one website Every device in the house Just this computer Slow even with no internet involved Fans loud, laptop hot

Slow on every website

Probably the connection.

If every site is slow on the computer, check the phone on the same WiFi. Slow there too means the connection, not the computer.

Why your NBN is slow

Slow on one website

That website.

If one site is slow and every other site is quick, the problem is that site. There is nothing to fix at home. Try it again later.

Every device in the house

The connection.

When the phone, the TV and the computer are all slow, the computer is fine. Start with the connection: an outage, a restart, then a speed test on a cable.

Check for an outage

Just this computer

The computer.

If the phone is quick on the same WiFi and the computer is slow, the internet is fine. Check what the computer is busy with, its storage and its updates.

Windows checksMac checks

Slow even with no internet involved

The computer.

Opening a photo, a document or a program that is already on the computer does not use the internet. If that is slow, the computer is the problem.

Windows checksMac checks

Fans loud, laptop hot

The computer.

Use it on a desk, not a bed or a pillow, and keep the openings clear. If it is still hot doing nothing, see what is busy in Task Manager or Activity Monitor.

Laptop overheating

What the results point to:

What you see, and where to go next

What you see	It points to	Go next
Every website is slow, on every device in the house	The connection or the WiFi	Why the NBN is slow, below
Only one website is slow	That website	Try again later. Nothing to fix at home
The phone is quick, the computer is slow	The computer	The computer's own signs, below
The computer is slow opening its own files	The computer	The checks for Windows or Mac, below
Fans loud, the computer hot	The computer, working hard or short of air	Laptop overheating, below
Slow in one room, quick near the modem	The WiFi coverage	A WiFi problem, not the computer

What if it’s the internet, not the computer?

If every device in the house is slow, the computer is not the problem, and no amount of work on it will help. Start with the connection instead.

• Nothing in the house will load. Check for an NBN outage at your address first, then restart the modem and the NBN box in the right order.
• Everything loads, but slowly. Why your NBN is slow sorts the WiFi from the evening rush from a fault in the line, with one test on a cable.
• The WiFi says connected, but nothing loads. That is its own problem, and connected without internet goes through it.
• Pages stall, then load in a rush, and video calls freeze. That is usually delay rather than speed, and what ping, jitter and packet loss are shows the difference.

On a Windows computer that is the only device with trouble getting online, there are a few network reset commands Microsoft documents, and they are in our Windows checks, SFC, DISM and CHKDSK, step by step, near the end.

Why is my computer so slow? The signs it’s the computer

The computer is the problem when it is slow at things that have nothing to do with the internet. Look for these:

• Slow to start, and slow opening its own files, photos and programs.
• The fans roar while you are only reading email, or the bottom of the laptop is hot.
• The drive is nearly full. A computer with almost no free space slows right down.
• Updates are waiting. A computer part way through an update, or one that has not been restarted in weeks, runs badly. A computer still on Windows 10 no longer gets Microsoft’s fixes; here’s what to do about Windows 10 end of support.
• Something is busy in the background. One program keeps the processor working while you do nothing.
• It got slow after something new was installed, or after a pop-up you clicked.
• It freezes, the pointer stops, or it restarts on its own.

Any one of these on its own is worth checking. Two or three together almost always mean the computer, whatever the internet is doing.

A computer that starts on a screen asking for a 48-digit key isn’t slow, it is locked: find the BitLocker recovery key first.

How do I check what’s slowing down a Windows computer?

Task Manager shows what the computer is busy with, and two Settings pages show the storage and the updates. Work through them in this order:

1. 1

   Close what you are not using, then restart

   Close the programs and browser tabs you do not need. Then select Start, then Power, then Restart. A restart on its own fixes a surprising amount.

2. 2

   Open Task Manager

   Hold down Ctrl and Shift and press Esc. If you only see a short list, select More details. It opens on the Processes tab, the list of everything running.

3. 3

   Put the busiest at the top

   Select the CPU heading at the top of the list, so the busiest programs sit at the top. A program you are not using that stays near the top is the one to ask about.

4. 4

   Check the storage

   Press the Windows logo key and I together to open Settings, then select System, then Storage. It shows how much space is used and how much is free.

5. 5

   Install waiting updates

   On Windows 11, open Settings, then Windows Update, then Check for updates. On Windows 10, it is Settings, then Update & Security, then Windows Update, then Check for updates. Restart when it asks.

Microsoft’s own tips to improve PC performance in Windows (opens in a new tab) (checked 20 October 2026) covers more, including turning off programs that start with the computer.

If it is still slow, still freezing or showing errors after that, Windows has built-in checks that find and repair damaged system files and drive errors. They are typed into a window as commands, and our step-by-step guide to SFC, DISM and CHKDSK gives each one with a copy button, so you never have to type it out yourself.

How do I check what’s slowing down a Mac?

Activity Monitor is the Mac’s version of Task Manager, and System Settings shows the storage and the updates. In this order:

1. 1

   Quit what you are not using, then restart

   Quit any apps you are not using. Then choose the Apple menu in the top corner, then Restart.

2. 2

   Open Activity Monitor

   Open the Applications folder, then the Utilities folder inside it, then Activity Monitor.

3. 3

   Look at what is busy

   Click CPU at the top of the window. Click a column heading to sort the list. An app you are not using that stays near the top is the one to ask about.

4. 4

   Look at the memory

   Click Memory and look at the memory pressure. Apple says green means the Mac is using its memory efficiently, yellow means it might eventually need more, and red means it needs more.

5. 5

   Check the storage and updates

   Choose the Apple menu, then System Settings, then General. Storage shows the free space. Software Update shows waiting updates.

Apple’s page if your Mac runs slowly (opens in a new tab) (checked 20 October 2026) lists the same causes: too little free space, an app that wants more memory than there is, apps left open, and problems with the disk.

For the disk, the Mac has its own check, Disk Utility’s First Aid, and our Mac guide to Disk Utility First Aid, Apple Diagnostics and Safe Mode walks through it, along with Apple’s own hardware test.

Why is my laptop overheating?

Usually because it is working hard, or because the hot air has nowhere to go. A laptop pulls air in and pushes it out through small openings, and a bed, a pillow or a blanket on the lap blocks them.

• Use it on a desk or a table. Apple’s advice for its laptops is a stable surface with good ventilation, never in bed, on a pillow or under bedding, and nothing put into the openings (Apple’s laptop temperature guide (opens in a new tab), checked 20 October 2026). The same sense applies to any laptop.
• Mind the room. Apple gives 10 to 35 degrees as the range to use its laptops in, and says not to leave one in a parked car.
• Know which noise is normal. Fans rush harder during heavy work and on soft surfaces, and that is part of the cooling. Grinding, whining or ticking is not normal: Microsoft’s page on its Surface laptops says a fan should never sound broken.
• Look for what is working it. If the laptop is hot while you are doing nothing, open Task Manager or Activity Monitor and see what is at the top, as above. A program stuck working in the background keeps the fans going.
• Restart it. On a Mac, Apple suggests closing and opening the lid or restarting when the fans run for no reason.

A laptop that is still hot on a desk, doing nothing, after a restart, or a fan that grinds, is a hardware matter, and that goes to the maker or a repair shop.

Why does my computer keep freezing?

A computer that freezes again and again has a problem that a restart only clears for a while. It can be a damaged system file, a drive with errors, a program that does not suit the computer, or the memory itself.

Before anything else, copy the photos and documents you cannot lose onto an external drive or into your cloud storage. A computer that freezes is a computer that may one day not start.

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Then restart it, install the waiting updates, and see if it settles. If it keeps freezing, run the built-in checks: on Windows, the SFC, DISM and Windows Memory Diagnostic checks, and on a Mac, First Aid and Apple Diagnostics. We have seen these checks fix a computer that kept crashing, and they are free and already on the computer.

My computer won’t turn on. What do I check?

Check the power first, because it is the most common cause and the easiest to fix.

• The power point and the charger. Make sure the cable is not damaged and is pushed fully into the computer and into a power point that works. Try another power point.
• Unplug everything else. Printers, drives, hubs, phones on charge: take them all out, then try again.
• On a Mac, hold the power button for about 10 seconds, or Touch ID on a laptop that has it, then press it again normally. Those are Apple’s own steps for a Mac that doesn’t turn on.
• On or not? If you hear it or see a light but the screen stays blank, the computer is on and the problem may be software. That is worth a call.

If nothing at all happens on a known good power point and charger, the computer has a hardware fault. We do not repair hardware, but we will tell you plainly what it is and help you decide what to do next.

When to call us, and when you don’t need to

You do not need us when a restart and the updates fixed it, when only one website was slow, or when the checks in our Windows or Mac guides came back clean and the computer is quick again. If every device in the house is slow, the computer is fine, and the connection is your provider’s to look at first.

Call us when you would rather not do it alone, when the checks say they found problems they could not repair, or when it is hard to tell whether it is the computer or the connection. Our home tech support sorts out computers, printers, phones and tablets at home, explained as we go. If the connection is the problem, an internet technician tests the line, the modem and the cabling on the same visit, and if it is only the back rooms, a WiFi technician fits better. We set things up, sort out the software and explain it; we do not repair screens, fit parts or recover files from a failed drive.

Not sure which it is? Send us a message with what the two-minute test showed, or ring 02 9188 1577.