Computer Randomly Turns Off [Causes and Fixes]

CG Director Author Christopher Harperby Christopher Harper   /  Updated 

When your computer randomly turns off, it can be pretty frustrating, especially if it’s happening frequently.

Whether you’re here from your first random crash, your seventh, or even just ahead of time for some reason, I’m going to help you diagnose and fix whatever is making your computer turn off involuntarily.

Let’s get into it.

What Are The Potential Causes of a Computer Randomly Turning Off?

The issues that cause your computer to randomly turn off vary, but will generally boil down to one of the following issues:

  • Power Delivery Issues
  • RAM Issues
  • OS Corruption
  • GPU Driver Issues
  • Storage Problems
  • Malware
  • Outdated or Misconfigured BIOS

I’ll discuss each of these issues in more detail, including how to fix them, below.

How To Fix Your Computer Randomly Turning Off

Power Delivery Issues

One of the most common reasons that a computer randomly turns off usually relates to power delivery issues, but the severity depends on the exact issue being faced. Let’s break them down:

If you’ve recently moved your PC, one thing you will want to check is the stability of your power cables plugged into your motherboard, specifically your motherboard power cable and 8-Pin CPU power cable.

CPU Power connectors

Beyond power connections inside your PC, also consider your wall or UPS power.

An insufficient Uninterruptible Power Supply (UPS) can easily lead to unexpected shutdowns, as can unstable wall power and loose external power cables.

If something is wrong with your wall power delivery, more than just your PC should be impacted. If it’s just your PC and you’re using a UPS, the issue is more likely an insufficient UPS.

Motherboard Power connector

Finally, you should also consider an unstable CPU or GPU overclock as a cause of an unexpected crash. Overclocking by nature stresses power delivery and requires higher voltages, which may not always work depending on the quality of your motherboard, card, or even PSU.

RAM Issues

Problems with RAM can also cause system instability. RAM issues can be slightly harder to verify, but generally come down to one of the following:

An unstable RAM overclock. If you’ve changed your RAM clock settings or XMP profile in your BIOS recently, this could be the cause.

Corrupted RAM usually only rises after months or years of extended use, and can be diagnosed with a Windows Memory Diagnostic or memtest86. Unfortunately, the only way to fix corrupted RAM is to replace it.

Finally, your RAM may simply be installed in the wrong slots. Double-check your motherboard’s manual and make sure that if there’s space, each RAM stick is at least one slot apart!

OS Corruption

System File Checker tool (SFC

Operating Systems are prone to corruption over a long enough period of time, especially when run for extended periods without restarts.

Fortunately, your operating system has built-in tools for fixing issues like this— I recommend using Windows’ System File Checker in order to fix this in the easiest way.

You may also need to have installation media (DVD or USB drive) on hand for the System File Checker to fall back on, or to do a deeper reinstall if SFC doesn’t fix your OS-related issues.

GPU Driver Issues

Even if seemingly nothing has gone wrong, over time GPU drivers can also become corrupted and need a full reinstall.

Especially if your power downs are happening during GPU-intensive tasks or when switching from GPU-intensive tasks, consider doing a clean reinstall of your GPU drivers.

Storage Problems

Storage problems can also lead to sudden shutdowns, but the fix is going to depend on the exact storage issue you have.

To diagnose potential issues with storage, get CrystalDiskInfo to get an up-to-date health reading on your drives.

Below, I’ve embedded a screenshot from the application with its own readings for my SSD:

SSD Readings from CrystalDiskInfo

SSD Readings from CrystalDiskInfo

If CrystalDiskInfo doesn’t show a healthy storage drive, you may just need to get a new storage drive to install Windows on.

Aging HDDs and SSDs can give way like this, sometimes years before they’re meant to and sometimes not once for a solid decade of use. Either way, diagnosing your storage is a vital first step if you expect something is wrong with your storage.

If CrystalDiskInfo shows a healthy storage drive, run a disk check.

On Windows, you can most easily do this by opening a Command Prompt with Admin permissions (try Windows Key + X!) and type the command “chkdsk /r” before hitting enter.

Then type “chkdsk /f” and hit Enter as well. At this point, you may be prompted to run the disk check at next restart— confirm and restart your PC to get started.

Note the speed of a disc check will depend on the speed of your storage. It can take hours for an HDD to complete a disc check, but SSDs across the board will generally progress through disc checks much faster.

The purpose of a disc check is to find and fix file system errors, rather than system file errors (like the System File Scanner, which you should try first).

Malware

Malware is a real concern, but fortunately should be easy to fix if you haven’t been infected with ransomware or a rootkit.

If you suspect malware is at fault, I highly recommend downloading and running Malwarebytes to run a scan on your entire PC.

Consider rebooting into Safe Mode while running the scan if you think there might be a deeper infection.

Change advanced startup options in Windows

Change advanced startup options in Windows

The easiest way to reboot Safe Mode in Windows is through typing “Change advanced startup options” in Start, selecting the option, and clicking the “Restart Now” button under Advanced Startup, which will enable a Safe Mode selection dialogue after a quick reboot.

Windows Advanced Startup

Windows Advanced Startup

Outdated or Misconfigured BIOS

Changed something in your BIOS recently, or haven’t touched or even thought about your BIOS for years?

If either of these scenarios sounds like you, you may be dealing with outdated or misconfigured BIOS. If a BIOS is misconfigured, the fix is pretty easy— just head back into it and reset your settings.

If you haven’t updated your BIOS, though, you’ll need to open up “System Information” in Windows to identify the BIOS you need.

System Information in Windows

System Information in Windows

“System Model” or “BaseBoard Product” should present you with the motherboard or prebuilt model that you need to find a BIOS update for.

Search for this information on your manufacturer’s site in order to find available BIOS updates, and follow their instructions to get your BIOS updated from there.

How To Diagnose The Problem With Event Viewer

Not sure what’s causing the problem and want to try and narrow it down? It’s time to open Start, Type “Event Viewer”, and get to work!

Event Viewer in Windows

Event Viewer in Windows

For the most part, you’ll want to eye “Critical” Administrative Events, but many Errors can be a cause for concern too.

“Critical” is usually limited to forced restarts or reboots, which makes it ideal for working out issues like this one. The main thing to look for is an “Event ID 41”, which is the PC recording a forced power off without a proper shutdown.

For more relevant event codes, head to ShellHacks.com for their Windows Shutdown Event IDs list, but 41 is the most likely one you’ll encounter.

To demonstrate how you can use Event Viewer, I won’t be forcing my PC through any hard restarts to create a bad Event.

However, I will open up my “Error” dropdown that visibly has quite a few errors accumulated over the past week! Fortunately, it’s pretty easy to identify the cause:

Errors in Event Viewer

Errors in Event Viewer

The problem source here is identified as “nvlddmkm”, which might initially sound like a bunch of garbage, but actually means something.

In this case, it’s referring to my Nvidia GPU drivers, which becomes clearer on closer inspection of the Events in question:

Error Source Details

Error Source Details

And the reason why the most recent occurrence of this event was nearly a full week before the day this article was initially written is that I fixed this problem by reinstalling my GPU drivers. A week later, Event Viewer reflects that my fix worked!

Using the practical knowledge from this example, you should be able to find the cause of your forced restarts in Event Viewer, if they’re being documented.

If not, I would just run down the list presented above in order, starting with Power Delivery issues.

FAQ

How do you tell if your PSU is too weak for your PC?

If your PSU is too weak for your PC, your GPU is most likely to be the culprit, since the GPU is by far the most power-hungry component in a modern PC.

I’ve written a guide on this situation and what to do in it already, but in the context of this situation, an additional note is worthwhile:

If the cause of your PC restarting is PSU-related, it should be tied to situations of high power consumption, like benchmarking software, professional renders, and modern games running with high or uncapped framerates.

How do you tell if your GPU is dying?

Is your PC or GPU on the older end, and you’re beginning to suspect your graphics card is kicking the bucket?

If you locked down your GPU as the cause for your restarts in this article and replacing the drivers is still presenting issues, your GPU may be dying.

If your graphics card is older than five years old, this may well be the case.

GPU Glitch Screen

For a guide on GPU failure and how to spot the signs, consider Alex’s article!

Aside from the numerous scenarios explored in that article, a common sign can be seen in graphics artifacts. Example artifacts have been illustrated above.

Over to You

And that’s it, for now! I hope that this article helped you diagnose and fix your PC’s random shut-offs.

If it didn’t, leave a comment below or in the Forums, and another member of the CGDirector team or I will do my best to help! Be sure to run through this guide and its tips first, though, especially with System File Checker and a Disk Check.

Until then or until next time, happy computing! And don’t forget to make a backup as soon as you can.

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Christopher Harper - post author

I have been a passionate devotee to technology since the age of 3, and to writing since before I even finished high school.

These passions have since combined into a living in my adulthood, and has made writing about myself very satisfying.

If you need any assistance, leave a comment below: it’s what I’m here for.

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