How to Fix a Computer That Keeps Restarting

A computer that keeps restarting most often loops because of overheating, a failing power supply, or Windows automatically rebooting after a crash before the error can be read. When a system reboots on its own during use, at the desktop, or in a cycle that never reaches the operating system, the cause sits in the hardware, the drivers, or a Windows crash-recovery setting rather than a single failed part. This article lists the causes of random reboots in order of probability, then walks through step-by-step solutions ordered from the setting that exposes the error to the deeper hardware tests.

The fixes cover disabling automatic restart to read the stop code, checking CPU and GPU temperatures, reseating and testing the RAM, updating or rolling back drivers, scanning for malware, reading the Event Viewer, and testing the power supply. Each solution states what it resolves and gives the exact procedure.

What Causes a Computer to Keep Restarting?

A computer keeps restarting because a fault forces the system to reboot, most commonly from overheating, a failing power supply, or Windows automatically restarting after a crash. The reboot is a symptom of a hardware fault or a software crash, and the causes rank by frequency. The common causes are listed below, most frequent first:

• Overheating trips the processor or graphics card thermal protection, which reboots the system to prevent damage.
• A failing power supply drops a rail under load, cutting power long enough to force a restart.
• Bad RAM corrupts data in memory, producing crashes that the system recovers from by rebooting.
• A driver conflict from a faulty or outdated graphics, chipset, or network driver triggers a stop error and reboot.
• Windows auto-restart on a crash reboots the system instantly on a blue screen, hiding the error behind the restart.
• Malware can destabilize the system or force reboots as part of its behavior.
• Failing storage with bad sectors corrupts system files, producing crashes and restart loops.

The timing of the reboot narrows the cause: a restart under heavy load points to heat or the power supply, while a restart at a fixed point in startup points to a driver or a corrupt system file. A system that reboots before reaching Windows belongs partly to the computer stuck on the boot screen guide, and one that powers off without restarting ties to the computer that turns off by itself guide.

Disable Automatic Restart to Read the Error

Disabling automatic restart resolves the inability to read the stop code by stopping Windows from rebooting instantly on a crash. Windows defaults to restarting on a system failure, which hides the blue screen and its stop code before it can be read.

Turning the setting off freezes the error on screen for diagnosis. Follow these steps:

1. Open System Properties by searching for ‘View advanced system settings’ in the Start menu.
2. Click Settings under Startup and Recovery, then find the System failure section.
3. Clear the ‘Automatically restart’ checkbox, so the system holds the blue screen instead of rebooting.
4. Record the stop code, such as WHEA_UNCORRECTABLE_ERROR or IRQL_NOT_LESS_OR_EQUAL, that the blue screen now displays.

The stop code names the failure class and directs the rest of the diagnosis: a WHEA error points to hardware or heat, while a driver name in the message points to a driver conflict. Reading and decoding the stop code is the core of the guide to fixing the blue screen of death, which lists what each common code indicates.

Check the CPU and GPU Temperatures

Checking the processor and graphics card temperatures resolves reboots caused by thermal shutdown. A processor that reaches roughly 100 degrees Celsius or a graphics card that exceeds its thermal limit triggers a protective reboot.

Monitoring the temperatures under load confirms or rules out heat. Follow these steps:

1. Install a monitoring tool such as HWiNFO or Core Temp to read the CPU and GPU temperatures in real time.
2. Watch the temperatures under load, since a reboot when the CPU nears 100 degrees Celsius confirms thermal shutdown.
3. Clean dust from the heatsinks and fans with compressed air, because clogged fins block airflow and raise temperatures.
4. Reseat the CPU cooler and reapply thermal paste if temperatures stay high, since dried paste and a loose cooler trap heat.

A system that reboots only under load and runs cool at idle is overheating, so the cooler mounting, the paste, and the case airflow need attention. A system that reboots at idle and stays cool points away from heat toward the power supply, memory, or a driver. Persistent heat that throttles performance also appears in the guide to fixing a slow computer.

Reseat and Test the RAM

Reseating and testing the RAM resolves reboots caused by faulty or unstable memory. Bad memory corrupts data and produces crashes that the system recovers from by rebooting, often with a memory-related stop code.

Testing the modules isolates a failing stick. Follow these steps:

1. Run Windows Memory Diagnostic by searching for it in the Start menu and restarting to scan the memory for errors.
2. Run MemTest86 from a USB drive for a longer, more thorough test that catches errors the built-in tool misses.
3. Reseat each module until both retention clips snap closed, since a partly seated stick causes intermittent errors.
4. Test one stick at a time to isolate a failing module, then disable any unstable XMP overclock in BIOS.

A memory test that reports errors confirms a failing stick that needs replacement, while a clean test with continuing reboots points elsewhere. An unstable XMP or memory overclock can cause errors on good modules, so disabling it tests the memory at its default speed. Correct module placement for stable operation appears in the guide to installing RAM.

Update or Roll Back Drivers

Updating or rolling back drivers resolves reboots caused by a faulty or incompatible driver. A graphics, chipset, or network driver that is outdated or freshly broken can trigger a stop error and reboot, and the fix depends on whether the problem followed an update. Follow these steps:

1. Identify the driver named in the stop code or the device that fails, focusing on the graphics and chipset drivers first.
2. Update the graphics driver from the AMD, Nvidia, or Intel website using a clean installation that removes the old version.
3. Roll back the driver in Device Manager if the reboots began right after a driver update, reverting to the previous version.
4. Update the chipset and storage drivers from the motherboard maker, since an outdated chipset driver can destabilize the system.

Reboots that began immediately after a driver update point to that driver, so rolling it back tests the link directly. A clean reinstall removes a corrupted driver that a simple update leaves in place. A driver stop error that also produces a blue screen ties to the blue screen troubleshooting guide.

Scan for Malware

Scanning for malware resolves reboots caused by malicious software destabilizing the system. Some malware forces reboots, corrupts system files, or consumes resources until the system crashes.

A full scan with a current tool removes the infection. Follow these steps:

1. Run a full scan with Windows Security, the built-in Microsoft Defender, rather than a quick scan, to check the entire system.
2. Run a second-opinion scan with a reputable on-demand tool such as Malwarebytes to catch what the first scanner misses.
3. Boot into Safe Mode if malware blocks the scan, since Safe Mode loads only essential drivers and services.
4. Remove detected threats and restart, then rescan to confirm the system is clean before resuming normal use.

A system that stops rebooting after malware removal had an infection as the cause. A clean scan with continuing reboots clears malware from the list and returns the diagnosis to hardware or drivers. Running a scan in Safe Mode catches threats that hide while the full operating system runs.

Read the Event Viewer for the Crash Source

Reading the Event Viewer identifies the source of the reboot from the logged error at the time of the crash. Windows records critical errors, including the Kernel-Power event that marks an unexpected shutdown, in the system log.

The entries point to hardware, a driver, or a power fault. Follow these steps:

1. Open Event Viewer by searching for it in the Start menu, then expand Windows Logs and select System.
2. Find the Critical and Error entries timestamped at the moment of the reboot to identify the failure.
3. Look for Kernel-Power event ID 41, which marks an unexpected power loss or hard crash consistent with a PSU or heat fault.
4. Note any driver or hardware error in the surrounding entries, which names the component or service that failed.

A Kernel-Power 41 event confirms the system lost power or crashed hard rather than restarting cleanly, pointing toward the power supply, heat, or memory. A driver error logged at the crash time names the faulty driver directly. The same logs help diagnose a system that powers off entirely in the computer that turns off by itself guide.

Test the Power Supply Under Load

Testing the power supply under load resolves reboots caused by a unit that cannot hold its rails when the system draws heavy current. A failing or undersized power supply drops a rail under load, cutting power long enough to force a restart, often during gaming or rendering. Follow these steps:

1. Reseat the 24-pin and 8-pin EPS connectors at the motherboard, since a loose plug drops power under load.
2. Test the power supply with a PSU tester or multimeter to confirm each rail holds its voltage within tolerance.
3. Swap in a known-good power supply of adequate wattage to confirm whether the original unit causes the reboots.
4. Confirm the wattage is sufficient for the processor and graphics card, since an undersized unit reboots under transient spikes.

A system that stops rebooting with a known-good power supply had a failing or undersized unit. How the power supply delivers and protects its rails appears in the explanation of how power supplies work, and sizing the unit for the load, including the transient spikes a graphics card produces, appears in the guide to PSU wattage. A power supply that cuts out entirely rather than rebooting ties to the guide to random PC shutdowns.

Key Takeaways

• Disable automatic restart first so Windows holds the blue screen and reveals the stop code that directs the diagnosis.
• Check CPU and GPU temperatures, since a reboot under load points to thermal shutdown from dust, dried paste, or a loose cooler.
• Test the RAM with MemTest86 and reseat the modules, because bad memory corrupts data and forces reboots.
• Update or roll back drivers, rolling back when the reboots began right after a driver update.
• Scan for malware and read the Event Viewer, where a Kernel-Power 41 event marks an unexpected power loss or hard crash.
• Test the power supply under load, since a failing or undersized unit drops a rail and reboots the system during heavy use.

Last Thoughts on a Computer That Keeps Restarting

A computer that keeps restarting is reacting to a fault, so the fix begins by exposing the error: disable automatic restart to read the stop code, then check temperatures, test the RAM, update or roll back drivers, scan for malware, read the Event Viewer for a Kernel-Power event, and test the power supply under load. The timing of the reboot and the stop code narrow the cause. Readers can continue with the fix for the blue screen of death, the fix for a computer that turns off by itself, the guide to random PC shutdowns, or the hub of common PC problems for related faults.