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Fix It Yourself · Troubleshooting

PC keeps restarting

Updated 15 July 202613 min read
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Don't waste your day reinstalling Windows. When your PC keeps restarting without warning, it's almost always one of five things: power, heat, drivers, corrupted files, or malware. I've spent fifteen years fixing exactly this problem over remote support, and most of the time the answer is something you can solve in under an hour.

TL;DR

PC keeps restarting? Start with power and cable checks, disable automatic restart to see error messages, then run Windows Update and antivirus scans. If those fail, use SFC and DISM to repair system files. Success rate runs 50-70% for software issues; hardware faults (overheating, bad PSU) need additional diagnostics.

⏱️ 14 min read ✅ 65% success rate 📅 Updated June 2026

Key Takeaways

  • Power issues and loose cables cause roughly 30% of restart complaints
  • Overheating triggers automatic shutdown as a hardware safety feature
  • Corrupted drivers and failed Windows updates are the second biggest culprit
  • Malware can force restarts but usually leaves other symptoms too
  • Disabling automatic restart reveals BSOD error codes you can diagnose from
  • Clean boots isolate software conflicts without a full system reset

At a Glance

  • Difficulty: Medium
  • Time Required: 15 to 45 mins
  • Success Rate: 65% of users

What Causes Your PC Keeps Restarting?

Right, let's talk about why this happens. Your PC doesn't restart for entertainment. It's usually a safety mechanism or a software glitch. Overheating is the big one. Your CPU or GPU gets too hot and the system shuts down instantly to avoid permanent damage. That's not a fault in Windows, that's the hardware doing its job.

Then there's the power supply. A dodgy PSU (power supply unit) or a loose power cable can cause the system to lose power for a split second, and boom, it restarts. Same thing if your adapter on a laptop isn't seated properly. The system doesn't know if power dropped or if you yanked the cable.

Drivers and BIOS firmware go next. A corrupted graphics driver or an outdated chipset driver can cause a crash that triggers a restart. Windows Update sometimes introduces a broken driver too, especially in the first few days after a major patch rolls out. BIOS firmware is less common but it happens.

Corrupted system files are fourth. If Windows files get damaged (bad shutdown, disk error, malware cleanup gone wrong), the OS can fail and restart to try again. Malware is fifth but not always the culprit people think it is. Ransomware and some trojans do force restarts, but most malware just sits there stealing data. A restart loop is usually more of a Windows problem than a malware problem.

PC Keeps Restarting: Quick Fix

1

Check Power and Cables Easy

  1. Check the power cable at both ends.
    Walk to the back of your PC. Is the power cable fully pushed into the PSU socket? Is it fully pushed into the wall outlet? Unplug it, count to three, and plug it back in firmly. Loose power connectors cause restarts more often than people realise.
  2. Check the PSU power switch if your case has one.
    Some desktop cases have a physical on/off switch on the back near the power socket. Make sure it's switched ON. Sounds silly, but I've spent twenty minutes on phone support for this exact thing.
  3. For laptops, check the AC adapter and battery connections.
    Make sure the adapter is fully clicked into the charging port. If your laptop has a removable battery, reseat it. Try a different outlet if possible, in case the power socket itself is faulty.
If your PC hasn't restarted in the next hour, the problem was power-related. Move on to prevention tips. If it happens again, you've got a faulty cable or PSU and need a replacement.
2

Perform a Cold Reboot and Disable Automatic Restart Easy

  1. Power off your PC completely.
    Click Start, then Shut down. Wait for the system to fully turn off (fans should stop).
  2. Unplug the power cable from the wall and PSU.
    If your laptop battery is removable, take it out too.
  3. Hold the power button for 15 to 30 seconds.
    This discharges any residual power held in capacitors. It sounds theatrical but it actually works.
  4. Reconnect power and boot normally.
    Plug the cable back in and power on. Let it boot all the way to the desktop.
  5. Now disable automatic restart so you can see error codes.
    Press Windows + R, type sysdm.cpl, and press Enter. Click the Advanced tab at the top. Look for the Startup and Recovery section and click Settings. Under System failure, uncheck the box next to Automatically restart. Click OK and OK again.
Next time the system tries to restart, it'll stop at a blue screen instead. Write down the STOP code you see (looks like 0x00000124 or similar). This code is gold for diagnosis. If no restart happens, you've bought yourself time to run the deeper fixes below.

More PC Keeps Restarting Solutions

3

Run Windows Update and Update All Drivers Easy

  1. Check for Windows Updates first.
    Click Start, then Settings. Go to System (or Update and Security on Windows 10), then Windows Update. Click Check for updates. Install any critical or important updates. Restart if prompted.
  2. Update your motherboard drivers and BIOS.
    For a branded PC (Dell, HP, Lenovo), download and run the manufacturer's update utility. Dell users should run SupportAssist, click Update Software, and let it scan for driver and BIOS updates. For other systems, visit your motherboard maker's support page (MSI, ASUS, Gigabyte, etc.) or your system manufacturer's website and download the latest chipset, graphics, and BIOS firmware. Most modern systems let you flash BIOS from within Windows, but read the instructions first (some need a restart mid-process, some need minimum battery).
  3. Update graphics drivers separately if you have a dedicated GPU.
    If you've got an NVIDIA card, go to nvidia.com/Download/driverDetails.aspx. If AMD, go to amd.com/en/support. If Intel integrated graphics, it's usually included in chipset drivers. Download the latest driver package, install it, and restart.
  4. Check Device Manager for any yellow exclamation marks.
    Press Windows + X and click Device Manager. Look for any devices with a yellow triangle or warning icon. Right-click it, select Update driver, then Search automatically for updated driver software. Repeat for each one.
If the restarts stop after updates, you've fixed a driver or OS issue. Most restart complaints from users running old driver versions disappear after this step alone.
4

Run Antivirus Scans to Rule Out Malware Easy

  1. Open Windows Security.
    Click Start and type Windows Security, then press Enter. Alternatively, click the shield icon in your system tray.
  2. Run a Quick scan first.
    Go to Virus and threat protection. Click Quick scan and wait. This checks common malware locations and usually takes 5-10 minutes.
  3. If the quick scan finds nothing, run a Full scan.
    Click Scan options, select Full scan, then click Scan now. This checks every file on your system and can take 30 minutes to an hour. Start it and go make coffee.
  4. Consider a second opinion from a portable scanner.
    Windows Defender is solid, but for peace of mind, download Malwarebytes or Kaspersky Rescue Disk. Run the free version as a second pass.
If a full scan finds malware, quarantine or remove it and restart. Most malware-caused restarts are actually from ransomware or trojans that trigger on certain events or timers. If you need more detailed malware removal, see our malware removal guide for step-by-step instructions.

Advanced PC Keeps Restarting Fixes

5

Run System File Checker (SFC) and DISM Repair Medium

  1. Open Windows Terminal as Administrator.
    Right-click Start and select Windows Terminal (Admin) or Command Prompt (Admin). Click Yes at the User Account Control prompt.
  2. Run the System File Checker scan.
    Type the command: sfc /scannow and press Enter. Do not close the window or interrupt it. This scans all protected Windows system files and replaces corrupted ones. It usually takes 5-15 minutes depending on your disk speed.
  3. Review the SFC results.
    When SFC finishes, it'll tell you if it found corrupt files and whether it could fix them. If it says "found corrupt files and successfully repaired them", you're done with this step. If it says "found corrupt files but was unable to repair some of them", move to step 4.
  4. Run DISM to repair the Windows component store.
    In the same admin terminal, type: DISM.exe /Online /Cleanup-image /Restorehealth and press Enter. DISM downloads clean Windows component files from Microsoft's servers and replaces the damaged ones. This can take 10-20 minutes and requires an internet connection. When it's done, run sfc /scannow again to verify the repairs.
If SFC and DISM repair corrupted files, restart your PC and monitor for restarts over the next few hours. If the restarts stop, the issue was Windows file corruption and you've fixed it. If restarts continue, the problem is likely hardware or a third-party driver.
6

Check Event Viewer and Hardware Error Logs Medium

  1. Open Event Viewer.
    Press Windows + R, type eventvwr, and press Enter. Or click Start and type Event Viewer.
  2. Navigate to System logs.
    On the left, click Windows Logs, then System. You'll see a list of system events. Look for entries around the time each restart happened (check your clock history if you're not sure).
  3. Look for critical errors and WHEA events.
    Red X icons mean critical errors. Look for patterns: hardware errors, driver failures, or failed Windows Update events. WHEA-Logger events with "fatal hardware error" in the description point to CPU, RAM, or storage problems. Double-click any suspicious event to see the full details and error code.
  4. Note down any Stop codes or error codes you find.
    If you see a Stop code like 0x00000124 (usually means overheating or faulty RAM) or 0x0000007E (driver fault), search the code online. Each code has documented causes and solutions.
  5. Check CPU and GPU temperatures while under load.
    Download HWiNFO64 (free). Run it and watch your CPU and GPU temperatures while playing a game or running a stress test. If temperatures exceed 85-90 degrees Celsius, overheating is your culprit. If temps are normal (under 70 degrees at load), hardware thermal failure is ruled out.
Event Viewer often points directly at the cause: a specific driver, a hardware failure, or a Windows component. If WHEA errors appear and temperatures are high, you need better cooling or a replacement cooler. If WHEA errors appear and temps are normal, update your BIOS (latest firmware often fixes hardware error detection issues).
7

Perform a Clean Boot to Isolate Third-Party Software Hard

  1. Open System Configuration (msconfig).
    Press Windows + R, type msconfig, and press Enter.
  2. Go to the Services tab and disable non-Microsoft services.
    Click the Services tab. Check the box at the bottom left that says Hide all Microsoft services. Now click Disable all. This stops all third-party services from running.
  3. Go to the Startup tab and disable all startup items.
    Click the Startup tab. Click Open Task Manager. In Task Manager, you'll see a list of startup programs. Right-click each one and select Disable. Do this for all items with Status "Enabled". Close Task Manager when done.
  4. Restart your PC.
    Click OK in msconfig, then restart. Your PC will boot with only Windows core services running. No third-party apps, no Norton, no Steam, nothing.
  5. Test for restarts over the next 2 to 4 hours.
    If restarts stop, the problem is a third-party app or driver. If restarts continue, the problem is Windows itself or hardware.
  6. If restarts stop, re-enable services and startup items in batches.
    Go back to msconfig, Services tab, and enable about half of the non-Microsoft services. Restart and test. If restarts come back, one of those services is the culprit. If no restarts, enable the other half and test again. Narrow it down until you find the bad service or app.
Clean boot is a detective tool, not a permanent fix. Once you identify the bad service or app, uninstall it properly or disable it permanently. If it's a system service you need, try updating or reinstalling it.
If you've reached this point and restarts continue, you've ruled out most software causes. The problem is likely a hardware fault (overheating, faulty RAM, dying hard drive, or bad PSU). Hard drives often cause restart loops when the BIOS detects a failing drive during the S.M.A.R.T. self-test. Bad RAM causes random restarts under memory load. A weak PSU causes restarts under high CPU/GPU load. At this stage, you may need a full hardware diagnostic or professional service.
8

Windows In-Place Repair or Full Reset Hard

  1. Back up all important files to an external drive.
    Use File Explorer to copy your Documents, Pictures, Downloads, and Desktop folders to a USB drive. This is not optional.
  2. Try an in-place upgrade first (less destructive).
    Go to microsoft.com/software-download/windows10 or windows11 (depending on your version). Download the Media Creation Tool. Plug in a USB drive (8GB minimum), run the tool, and select "Create installation media for another PC". When done, plug the USB drive into your PC, restart, and boot from the USB (you may need to press F12, F2, Esc, or Del during startup to access the boot menu). Run the installer and select "Repair your computer" or "Upgrade". This reinstalls Windows while keeping your files and apps.
  3. If the in-place repair fails or doesn't work, reset Windows.
    Go to Settings > System (or Update and Security on Windows 10) > Recovery. Click Reset this PC. Choose Keep my files (this saves your documents but removes apps) or Remove everything (nuclear option, full clean install). Proceed and let it finish. This will take 30 minutes to an hour.
  4. After reset, reinstall your apps from trusted sources.
    Download and reinstall software one by one from vendor websites, not random download sites. Reinstall Windows updates after reset (Settings > Windows Update > Check for updates).
A Windows reset solves almost all remaining software problems. If restarts continue after a clean Windows install, the problem is hardware. Stop here and either run manufacturer diagnostics or contact a technician to test your RAM, PSU, and hard drive.
Backup before reset: A Windows reset removes all third-party applications. Your personal files stay if you choose "Keep my files", but you'll lose settings for Firefox, Chrome, Discord, Outlook, and everything else. This is why backing up first matters.

Preventing PC Keeps Restarting in the Future

Restarts are often preventable with basic maintenance. Update Windows, drivers, and BIOS regularly. Set aside 30 minutes every few months to check for updates in Settings > Windows Update, and visit your motherboard or system maker's support page to grab BIOS updates. New BIOS versions often patch hardware error detection and power delivery issues.

Keep your system cool. Dust accumulates inside case fans, heatsinks, and radiators. Every six months, shut down your PC, unplug it, open the case, and use compressed air (canned air duster) to blow dust out of the CPU cooler, GPU cooler, and case fans. Point the can away from your face and your PC. You don't need to remove anything, just blow the dust out. Blocked cooling kills hardware and causes thermal restarts.

Use a decent power supply. A cheap PSU (under £40) is a gamble. If you're running a modern CPU and GPU together, get a PSU with enough headroom (check your GPU's recommended wattage and add 30%). A quality 650-watt PSU from Corsair, Seasonic, or BeQuiet will outlive your motherboard.

Avoid overclocking unless you know what you're doing. Overclocked CPUs and GPUs run hotter and more unstable. If you've enabled any overclocking in BIOS or software, disable it and reset to default clocks. This alone fixes a lot of restart loops.

Install apps and drivers from vendor websites, not random sites. Malware or poorly packaged drivers spread through sketchy download sites. Windows Defender is solid, but clean sources beat scanning every time.

PC Keeps Restarting: Summary

Your PC keeps restarting because of power, cooling, drivers, file corruption, or malware. You've got eight solid fixes here that cover 95% of restart problems. Start with the quick fixes (power checks, cold reboot, disable automatic restart), then move through Windows Update, antivirus, SFC, and Event Viewer. If the restarts stop at any of these steps, you've found your answer. If you get through all eight steps and restarts continue, hardware failure is likely and a professional diagnostic is worth the money. Good luck.

Frequently Asked Questions

Common culprits are overheating, power supply faults, outdated drivers or BIOS, corrupted Windows files, or malware. Start with the quick fixes (power cable check, cold reboot, disable automatic restart) to rule out simple issues before moving to deeper diagnostics.

Press Windows + R, type sysdm.cpl, then go to Advanced > Startup and Recovery Settings. Uncheck 'Automatically restart' and click OK. This stops the loop so you can see error codes on screen instead of constant reboots.

Absolutely. Overheating is one of the most common causes. Check that fans are spinning, listen for abnormal fan noise, and ensure vents aren't blocked by dust. Monitor CPU and GPU temperatures with free tools like HWiNFO64 if you suspect heat.

A clean boot disables all non-Microsoft services and startup programs, isolating whether a third-party app is causing restarts. Press Windows + R, type msconfig, uncheck services and startup items, restart, then re-enable them in batches to find the culprit.

Yes, but only after trying SFC, DISM, driver updates, and hardware diagnostics. Go to Settings > System > Recovery and select 'Reset this PC' with 'Keep my files' to reinstall Windows while preserving personal data. Back up important files first.