How to Fix a Computer That Restarts Randomly

Random computer restarts indicate hardware overheating, power supply problems, or software conflicts. These systematic troubleshooting steps identify and resolve the most common causes of unexpected reboots.

1. Check system temperatures. Download HWiNFO64 or Core Temp to monitor CPU and GPU temperatures. Run the program and observe temperatures under normal use. CPU temperatures above 80°C (176°F) or GPU temperatures above 85°C (185°F) indicate overheating. Clean dust from fans and heat sinks using compressed air if temperatures are excessive.
2. Test system memory. Press Windows + R, type 'mdsched.exe', and press Enter. Select 'Restart now and check for problems'. The computer will restart and run Windows Memory Diagnostic. After the test completes and Windows loads, check Event Viewer (eventvwr.msc) under Windows Logs > System for memory errors. Replace RAM modules if errors are detected.
3. Update device drivers. Right-click Start button and select Device Manager. Look for devices with yellow warning triangles or red X marks. Right-click problematic devices and select 'Update driver'. Focus on graphics, network, and storage drivers first. Download the latest drivers directly from manufacturer websites rather than using Windows automatic updates.
4. Disable automatic restart on system failure. Right-click This PC and select Properties. Click 'Advanced system settings', then 'Settings' under Startup and Recovery. Uncheck 'Automatically restart' under System failure. This prevents automatic restarts and displays blue screen error codes that help identify the specific problem causing crashes.
5. Check power supply connections. Shut down the computer and unplug the power cord. Open the case and verify all power connections are firmly seated. Check the 24-pin motherboard connector, 8-pin CPU power connector, and PCIe power connectors for graphics cards. Reseat any loose connections. Look for swollen capacitors or burn marks on the power supply unit.
6. Run system file checker. Open Command Prompt as administrator by right-clicking Start and selecting 'Windows Terminal (Admin)'. Type 'sfc /scannow' and press Enter. Wait for the scan to complete. If corrupted files are found, run 'DISM /Online /Cleanup-Image /RestoreHealth' followed by 'sfc /scannow' again to repair system files.
7. Check event logs for patterns. Press Windows + X and select Event Viewer. Navigate to Windows Logs > System. Look for critical errors, warnings, or unexpected shutdown events around the times restarts occurred. Note error codes and search Microsoft support or manufacturer websites for specific solutions. Pay attention to Kernel-Power events which indicate hardware issues.