How to Fix It When a Computer Randomly Restarts

Troubleshooting a PC that keeps restarting

A computer that restarts at random can become all but unusable. To make matters worse, this typically occurs without a warning, error message, or apparent cause. Our guide to fixing it when a computer randomly restarts will help you resolve this elusive problem.

Why Does My Computer Restart Without Warning?

Several problems can cause a computer to restart without warning, but most fall under a few broad categories.

  • A problem with how power is delivered to the PC.
  • Overheating hardware.
  • Defective hardware.
  • A software or operating system bug.
  • Malware and ransomware.

How to Fix It When a Computer Randomly Restarts

The wide variety of issues that could cause a random restart can make finding the cause difficult. The steps below are in an order that will help you find the root cause of the issue.

  1. Disable automatic restart on system failure. This change won't fix the problem, but it may stop the computer from restarting if a software or operating system issue is the cause. Preventing a random restart may give you a chance to see an error message and better identify the cause.

  2. Check the power cord and its connection to both your PC and the power outlet.

    Sometimes the issue is as simple as a loose power cord. I've personally experienced a baffling restart caused by a loose power cord that would restart my PC whenever I accidentally grazed it with my foot. It happens!

  3. Examine the power outlet that delivers power to your computer. Pay attention to other devices connected to the outlet when the computer restarts. Do they also lose power? If so, the problem could be the wall outlet and not the computer.

  4. Closely check your computer's power and restart buttons. Make sure they're clear of objects, pets, and siblings. Move anything that could accidentally activate the power or restart button.

  5. Look for signs that your PC is overheating. Alternatively, you can use software to test your computer's CPU temperature in real-time. Every PC has a series of sensors that monitors internal temperatures. They will force a shutdown if temperatures rise high enough to damage the PC's hardware.

    The shutdown temperature varies by PC and sometimes by the sensor, but temperatures over 100 degrees Celsius usually mean trouble.

    Is heat the problem? Our PC cooling guide can help you fix it.

  6. Give your PC a gentle shake. A loose internal connection might cause a random restart. Shaking or moving the PC could trigger the problem. If it does, that's a good sign the issue lies with the internal hardware and will need a repair.

  7. Run Windows Update. Windows Update will install the latest drivers and fixes for your PC's hardware. Updating could fix the issue if caused by a software, driver, or operating system bug.

  8. Uninstall recently installed software. The problem could be caused by a software bug. If the restarts began recently, try uninstalling any software installed before the issue started.

  9. Install and run antivirus software if you don't already have it installed. Remove any malware that it finds. Malware doesn't usually restart a computer, as this rarely benefits its creator. Still, malware can cause numerous unexpected issues leading to a random restart.

  10. Reset Windows with the Keep my files option. A reset will remove most software but keep some files and settings. It could remove software or settings that are causing the random restart.

  11. Reinstall Windows. This more demanding alternative to a reset will completely wipe Windows, including all software and files, offering a fresh start.

    If random restarts persist after this step, the problem is likely your computer's hardware, not Windows or installed software.

  12. Open your computer and clean any dust or dirt. Also, check internal connections to make sure they're not loose.

  13. Remove any recently installed hardware upgrades. New hardware can cause unexpected conflicts. Reverting to your prior hardware might fix the problem.

  14. If you are using a desktop PC, replace the power supply. The power supply converts power from your wall outlet to power various PC components can use. A problem with the power supply can cause random restarts, among other issues.

  15. Closely examine the motherboard and other internal components that are visible. Look for signs of defective hardware, such as a bulging battery (if you use a laptop) or bulging capacitors.

    You may not be able to fix these issues at home, but identifying them will help a repair shop find and fix the problem.

  16. Does your computer still randomly restart? The problem is likely a hardware defect with a critical component in your computer. You will need to have the computer fixed by a repair shop or the computer's manufacturer if it's still under warranty.

  • Why does my computer restart when I shut it down?

    This error is usually due to software or driver issues. Usually, the easiest fix is to go to Control Panel > Power Options > Choose what the power buttons do > Change settings that are currently unavailable and uncheck the box next to Turn on fast startup. Otherwise, check for driver updates.

  • Why does my computer randomly restart while playing games?

    Overheating is the most likely culprit when a game restarts while you're gaming. Make sure your PC has enough space to vent air or try other ways to keep your computer cool.

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