Computer Keeps Freezing? Here's What's Actually Causing It (and How to Fix It)

First: how to safely shut it down when it’s frozen

Before working out why it's freezing, you need to get out of the freeze. How you do that depends on whether the mouse still moves.

That single observation is the most useful diagnostic in the whole article. Note it before you do anything else.

Try Ctrl + Alt + Del first

Press Ctrl + Alt + Delete on the keyboard. If the screen with options for Sign Out, Lock, Switch User and Task Manager appears, the freeze is in a single program rather than the whole system.

Open Task Manager from that screen, find the program with "Not Responding" next to it, and click End Task. Most software-side freezes clear at this point.

If Ctrl + Alt + Del does nothing at all, the freeze is deeper. Move to the next steps.

What to do if the mouse still moves (and what it tells you)

If the cursor moves around the screen but you can't click anything, you're looking at a software hang. Programs aren't responding to clicks but the operating system is still alive underneath.

This rules out a lot of hardware causes. The mouse moving means the system is processing input, just not letting you do anything with it.

Try Ctrl + Shift + Esc to open Task Manager directly, skipping the security screen. Force-close the program that's hanging. If Task Manager won't open either, hold the power button on your computer for 10 seconds to do a hard shutdown.

What to do if nothing responds at all

Mouse won't move, keyboard does nothing, screen frozen. This is much more likely to be a hardware issue or a deep system fault, not a single program crashing.

Hold the power button on your computer for about 10 seconds until it shuts off completely. On laptops, the same applies. If holding the power button does nothing, unplug the power cable and remove the laptop battery if it's removable.

When the computer is off, wait 30 seconds, then power it back on. If it boots normally, the freeze was temporary. If it freezes again on startup or shortly after, you've got a deeper problem we'll work through below.

What not to do (and why)

Don't keep clicking the mouse hoping something will respond. Click events queue up and can cause more weird behaviour when the system unfreezes.

Don't pull the power cable on a desktop unless the power button has failed. The proper hard shutdown via the 10-second power button hold is gentler on the drive than yanking power.

Don't do this every time it freezes either. If you're forced to hard-shut-down a computer multiple times a day, you're risking file system corruption on top of whatever's already broken. That's the point where it stops being a wait-and-see problem.

Software reasons your computer freezes

Roughly half the freezing jobs we get called out for turn out to be software. The good news with software causes is that they're usually fixable without replacing anything.

A recent Windows update

Windows pushes major updates regularly, and they don't always play nicely with every machine. If your computer started freezing within a few days of a Windows update installing, that's a strong suspect.

You can roll back the most recent update through Settings, Windows Update, Update history, Uninstall updates. Pick the most recent one, restart, and see if the freezing stops.

Windows can also freeze briefly during the system restore point creation that runs after big updates. If your freezes are short (30 seconds to a couple of minutes) and only happen occasionally, this might be the cause and not actually a fault.

A specific program crashing

If the freeze always happens when you open the same program, or when a specific website loads, you're looking at a software conflict rather than a system problem.

The fix is usually to update or reinstall the misbehaving program. Check the publisher's website for a current version. If that doesn't help, uninstalling and reinstalling cleans up corrupted files that the in-place update can't reach.

Browser hangs are especially common. If Chrome or Edge freezes regularly, check the extensions. One bad extension can lock the whole browser, and depending on the system, can drag the entire computer down with it.

Graphics drivers (especially Nvidia)

GPU driver problems are one of the top three software causes of freezing we deal with. Nvidia drivers in particular have a reputation for occasional bad updates that cause system hangs across the country until the next patch comes out.

The fix is to roll the driver back to the previous version, or to download a fresh driver direct from the GPU manufacturer or your laptop's support site. For laptops, the manufacturer's site (Dell, HP, Lenovo, ASUS) is usually a better source than Nvidia's because the driver's been validated against your specific machine.

If this section sounds familiar, it's because graphics driver issues also cause blue screen errors. The two problems share a lot of the same root causes.

Out of memory or storage

Computers freeze when they run out of working memory or out of free disk space. Both are surprisingly common, especially on machines that have been in service for a few years and have accumulated a lot of background programs.

Check Task Manager (Ctrl + Shift + Esc) and look at the Performance tab. If memory usage is sitting above 90% all the time, your computer is constantly swapping data to disk, which slows everything down and can trigger freezes when something demands a burst of memory.

Free disk space matters too. Windows needs at least 10 to 15 percent free on the C drive to operate smoothly. If you're below that, deleting old files, clearing the Downloads folder, and uninstalling unused programs is the first fix.

Malware

Less common than it used to be, but still worth ruling out. A computer that's been infected with cryptomining malware will run hot and slow because the malware is using your processor flat-out in the background.

Run a full Windows Defender scan from Settings, Privacy & Security, Windows Security, Virus & threat protection, Scan options, Full scan. It'll take a couple of hours but it's worth doing if nothing else explains the freezing.

If Windows Defender turns up nothing and you're still suspicious, a second-opinion scan with Malwarebytes (the free version is fine for this) catches things Windows Defender sometimes misses.

Hardware reasons your computer freezes

When software fixes don't help, hardware is the other major category. Hardware problems are harder to diagnose without tools, but the symptoms tend to be more distinctive once you know what to look for.

A failing hard drive or SSD

The single most common hardware cause of computer freezing we see is a drive that's on the way out. Spinning hard drives older than 5 to 7 years are prime suspects. SSDs can also fail, usually with warning signs in their SMART data before they go completely.

The signature symptom is freezes that get worse over time. The computer might run fine for an hour, then freeze for 30 seconds when it tries to read or write a specific file, then come back. As the drive deteriorates, the freezes get longer and more frequent.

If you're seeing this pattern, get your data backed up immediately. Don't wait until the weekend. A drive that's making the whole computer freeze can fail completely with no warning, and once it's gone, the data goes with it.

Bad or loose RAM

Faulty memory or RAM that's not seated properly causes random freezes that don't follow any pattern. The computer might freeze hard with no warning, sometimes restart on its own, and occasionally show a blue screen with a memory-related error code.

Loose RAM is more common than faulty RAM. If a desktop has been moved or knocked, or a laptop's been dropped, a stick of RAM can wiggle out of its slot just enough to cause intermittent freezes.

Windows has a built-in memory test tool. Search "Windows Memory Diagnostic" in the Start menu, click Restart now, and let it run. It'll check the RAM during boot and flag any errors when Windows starts back up.

Overheating

Computers that run hot freeze. The processor and graphics card both have built-in temperature limits, and when they're hit, the system either slows dramatically or hangs entirely to protect the silicon.

Overheating happens for two main reasons in homes: dust buildup blocking the cooling fans and vents, or thermal paste between the processor and heatsink drying out. Both get worse over time. Laptops especially, because the cooling system is more cramped and the vents are easier to block.

If your computer is freezing only when you've been using it for a while, especially while gaming or doing video work, overheating is the strong suspect. The fix is usually a good cleanout and sometimes a thermal paste replacement.

A dying power supply (especially after a blackout)

In a desktop, the power supply is what feeds clean stable voltage to every other component. When a power supply starts to fail, you get random freezes, random shutdowns, and components behaving erratically.

Australian storm season is when this pattern becomes obvious. A sudden blackout, a lightning strike nearby, or even a brownout where the voltage dips can damage a power supply that was previously fine.

Surge protectors help but they're not foolproof, and older surge boards lose their protection capacity over time.

I had one come in recently after a big storm. Customer had been running fine for years, then started getting random freezes and the occasional unexpected shutdown the week after a blackout.

The hard drive looked OK, the RAM tested fine, but the power supply was producing voltage that was just slightly out of spec under load. Replaced the PSU, problem gone.

If your computer started misbehaving in the days or weeks after a power event, the power supply is the first thing to look at. Without proper testing tools it's hard to confirm yourself, but if other diagnoses don't fit, it's the next suspect.

Loose internal connections

Less common but worth knowing. Cables inside the computer that connect the storage drives or the front panel buttons can work loose over time, especially in machines that have been moved house or are stored in vibrating environments.

The symptom is freezes that come and go with no pattern, often improving briefly after the computer's been gently knocked or moved. If this matches what you're seeing, opening the case and reseating cables is worth a try, but only if you're comfortable doing it.

How to figure out which one it is

Going through every possible cause one by one is exhausting. The four questions below narrow it down quickly.

Does the mouse still move?

If yes, the freeze is software. The operating system is still alive, just not responding to clicks. Focus your diagnosis on programs, drivers, and Windows itself.

If no, hardware moves up the suspect list. Especially RAM, storage, or PSU. Software can occasionally cause hard freezes too, but the odds tilt heavily toward hardware once the mouse goes dead.

Is it random or predictable?

Random freezes (no consistent trigger, no pattern) skew hardware. RAM faults, failing storage, dying power supplies, and overheating all tend to be unpredictable.

Predictable freezes (always when opening Photoshop, always when waking from sleep, always five minutes into a specific game) skew software. Drivers, app conflicts, and specific Windows components are usually behind these.

Does it happen cold or only after running for a while?

Freezes from cold boot or within the first few minutes point to startup software conflicts, a failing drive, or a deep Windows fault.

Freezes only after the computer's been running 30 minutes or more point to overheating. The system has had time to warm up, the fans are struggling, and the processor or graphics card is hitting its thermal limit.

What Reliability Monitor and Event Viewer can tell you

Most articles point you at Event Viewer, which is a pain to read. There's a friendlier tool called Reliability Monitor that nobody talks about.

Search "Reliability Monitor" in the Start menu. You'll see a graph of the last few weeks with red X marks at every crash or hang, often with a one-line description of what happened. This alone tells you whether your freezes correlate with a specific program, a Windows update, or no obvious cause at all.

If Reliability Monitor doesn't have what you need, then it's worth opening Event Viewer (Windows + X, Event Viewer, Windows Logs, System) and looking for red errors or yellow warnings at the time of the freeze. AppHang or Disk warnings around the freeze time tell you a lot.

Things you can safely try yourself

Before calling in a tech, here are the steps that fix a meaningful share of freezing problems with no specialist tools.

A clean restart

Power the computer off completely (Shut down, not Sleep), wait 30 seconds, and turn it back on. This clears stale processes and is often enough on its own.

If you've only been using Sleep or Hibernate for weeks at a time, a proper reboot might be all you need. Windows accumulates state over long uptimes that can cause weird behaviour.

Check for Windows updates

Go to Settings, Windows Update, Check for updates. If updates have been waiting to install, getting them current can fix bugs that cause freezing.

Equally, if a recent update is the suspected cause, the rollback option is in Update history, Uninstall updates.

Check storage health

Open Command Prompt as Administrator (search "cmd", right-click, Run as administrator) and type chkdsk C: /f /r. It'll prompt you to schedule the scan for the next reboot.

Restart the computer and let it run. It takes anywhere from 30 minutes to a few hours depending on the drive size. If it finds bad sectors, your drive is on the way out and your priority shifts to backing up immediately.

Update graphics drivers

For laptops, go to your laptop manufacturer's support page (Dell, HP, Lenovo, ASUS) and download the latest graphics driver for your model. For desktops with a separate graphics card, get the driver direct from Nvidia or AMD's website.

Use the Express install option rather than Custom unless you know exactly what each component does. The Custom install can leave behind drivers that conflict with the new ones.

Run a memory test

Search "Windows Memory Diagnostic" in the Start menu, click Restart now and check for problems. The computer will reboot, run the test during startup, and report any errors when Windows opens back up.

If the test finds errors, one of your RAM sticks is faulty. Replacement is usually straightforward on desktops, more involved on laptops where the RAM might be soldered to the motherboard.

Clean out the dust

If you're confident opening the case, dust buildup on fans and vents is one of the most common overheating causes. A can of compressed air aimed at the fans, vents, and heatsinks (with the computer off and unplugged) clears most of it.

For laptops, the safer bet is to take it to a tech for a proper internal cleanout if you've never opened one before. The screws are tiny, the ribbon cables are fragile, and a clip snapped off costs more to replace than the cleanout would have cost.

If the basics aren't sorting the freezing, or you'd rather not pull the case apart yourself, that's where we come in. A proper diagnosis with the right tools usually finds the cause within a single visit.

When freezing means something more serious

Most freezing problems are inconvenient but not urgent. A few patterns mean you should stop using the computer and act fast.

Random shutdowns alongside the freezing

A computer that freezes is annoying. A computer that randomly shuts itself off is failing.

If the freezes are happening alongside spontaneous shutdowns, the suspect list narrows to overheating, dying power supply, or a failing motherboard. Continuing to use the computer in this state risks making the damage worse and potentially losing data.

Strange noises or smells from the computer

Clicking or grinding sounds from a desktop hard drive mean the drive is failing mechanically. The clicking is the read-write head making contact with the platter, which destroys data each time it happens.

If you hear this, stop using the computer now. Every additional minute of operation reduces what we can recover. Power it off, leave it off, and arrange a recovery service.

The same applies to any burning smell or visible smoke. That's hardware actively failing, often the power supply or a failing capacitor on the motherboard. Unplug it from the wall and don't turn it on again until a tech has looked at it.

Blue screen of death codes

A computer that's both freezing and showing blue screen errors is sending you a clearer message than freezes alone. The error code on the blue screen often points to a specific cause.

PAGE_FAULT_IN_NONPAGED_AREA usually means RAM. KERNEL_DATA_INPAGE_ERROR usually means storage. IRQL_NOT_LESS_OR_EQUAL usually means a driver.

Take a photo of the blue screen the next time it happens. The error code at the bottom is the most useful diagnostic information you can give a tech.

When your data is at risk (back up NOW)

If anything in this article points to your storage drive failing, back up your important files immediately. Symptoms include slowing freezes that get worse over time, clicking sounds, the chkdsk scan finding bad sectors, or storage-related blue screen errors.

Don't wait for a weekend, don't wait for an external drive to arrive in the post. Cloud backup (OneDrive, Google Drive, Dropbox) for documents, photos, and anything irreplaceable. Plug in any external drive you have and copy the essentials across.

We see customers every month who waited too long. By the time they call us, the drive is dead and what we can recover is partial at best, often at significant cost. The window between "freezes are getting worse" and "drive is gone" can be days, sometimes hours.

If your computer is showing any of the serious warning signs above, stop using it and get in touch. Continuing to run a failing machine doesn't fix it; it usually makes recovery harder and more expensive.

Done with the freeze and crash routine?

If your computer's been freezing for weeks and you've had enough, we can help. Our techs diagnose freezing computers all day every day, work with every common brand of laptop and desktop, and can usually identify the cause within a single visit. When the upgrade cycle wraps up, the legacy servers, desktops, and networking gear still need to leave the building cleanly. North American businesses work with IT asset disposition specialists like Michaels Global Trading to recover residual value and ensure certified, data-sanitized disposal

Repairs, parts replacement, data recovery, or honest advice when it's time to replace. Get in touch with Jim's IT and we'll send someone out to take a proper look.

Frequently Asked Questions

Why does my computer freeze randomly?

Random freezes with no obvious pattern usually point to hardware. The top three causes we see are failing storage drives, faulty or loose RAM, and overheating from dust buildup.

Software can also cause random-feeling freezes, especially graphics driver conflicts and Windows updates that haven't installed cleanly. Working through Reliability Monitor (search it in the Start menu) often reveals a pattern that didn't seem obvious from the outside.

How do I unfreeze a computer that won't respond at all?

Hold the power button down for about 10 seconds until the computer shuts off completely. Wait 30 seconds, then power it back on. On laptops, if holding the power button does nothing, unplug the charger and remove the battery if it's removable.

This is fine to do once. If you find yourself doing it daily, the computer has a deeper problem that won't fix itself, and the repeated hard shutdowns can cause file system corruption on top of whatever else is wrong.

Is freezing a sign my hard drive is dying?

It can be, especially if the freezes are getting worse over time and they happen when the computer tries to read or write specific files. Failing storage is the single most common hardware cause of freezing we see across the network.

Run chkdsk C: /f /r from Command Prompt with admin rights. If it finds bad sectors, the drive is degrading and you should back up your data now. Mechanical clicking or grinding sounds from a desktop hard drive mean the failure is already underway and you should stop using the computer immediately.

Can a Windows update cause my computer to freeze?

Yes, fairly regularly. Windows pushes updates that don't always play nicely with every machine, especially with older graphics cards or unusual hardware setups.

If your freezing started within a few days of a Windows update, you can roll it back through Settings, Windows Update, Update history, Uninstall updates. If the freezing stops after the rollback, you can choose to delay reinstalling that update until Microsoft pushes a fix.

Why does my laptop freeze only when plugged in (or only on battery)?

If it freezes only when plugged in, the most common cause is a failing charger or a damaged power port. The voltage being delivered to the laptop is unstable enough to cause hangs.

If it freezes only on battery, the battery itself is usually the issue. Old laptop batteries can deliver inconsistent voltage as they degrade, especially under heavier loads. A new charger or battery is usually a straightforward fix once the cause is confirmed.

How do I know if my RAM is causing freezes?

Search "Windows Memory Diagnostic" in the Start menu and run it. The computer reboots, tests the RAM during startup, and reports errors when Windows opens back up.

If the test finds errors, replace or reseat the RAM. If the test passes but you still suspect RAM, downloading MemTest86 and running it from a USB stick gives a more thorough multi-pass test that catches faults the built-in tool sometimes misses.

Should I worry if my computer freezes once a week?

Once a week is in the "annoying but not urgent" zone for most people. It's worth working through the basic fixes (Windows updates, driver updates, a chkdsk scan, a memory test) but it's not an emergency.

The point to start worrying is when the frequency increases. Once a week becomes twice a week becomes daily. That trajectory means a fault is getting worse, and it's worth diagnosing properly before something fails outright.

Is it worth fixing an old computer that keeps freezing?

Depends on what's wrong, what the computer is, and what you use it for. A 4-year-old laptop with a failing hard drive is usually worth fixing because the drive is cheap to replace and the rest of the laptop has years of life left.

A 10-year-old desktop with a failing power supply, ageing motherboard, and a slow spinning hard drive is usually not worth it because you'll be replacing components for the next year and still have an old machine.

For most home users, the rough rule we use is that a repair worth more than half the cost of a comparable new machine deserves a proper conversation about whether replacement makes more sense. Refurbished business laptops with warranty are a solid alternative if budget is the concern.