Computer Keeps Restarting? How to Fix It

A computer that keeps restarting on its own is one of the most frustrating problems to troubleshoot because you barely get time to do anything before it reboots again. The causes range from software updates to failing hardware. Here’s how to narrow it down.

Software Causes

Windows Update Restart Loop

The most common cause: a Windows update fails during installation, the system restarts to try again, the update fails again, and the cycle repeats.

• Boot into Safe Mode (hold Shift while clicking Restart, then Troubleshoot → Advanced → Startup Settings → Safe Mode)
• Open Command Prompt as Administrator
• Run: wusa /uninstall /kb:XXXXXXX (replace with the failing update KB number from Update History)
• Or run: DISM /Online /Cleanup-Image /RestoreHealth followed by sfc /scannow

Bad Driver

A recently installed or updated driver can cause restart loops, especially graphics and chipset drivers:

• Boot into Safe Mode
• Open Device Manager and roll back the most recently updated driver
• Or use System Restore to go back to before the driver was installed

Malware

Some malware causes restart loops either intentionally (ransomware) or as a side effect of system damage:

• Boot into Safe Mode with Networking
• Run a full scan with Windows Defender or download Malwarebytes
• If malware is found and can’t be removed, a factory reset may be necessary

Hardware Causes

Overheating

CPUs have thermal protection that shuts down or restarts the computer to prevent damage:

• If the computer runs for a while before restarting (10–30 minutes), overheating is likely
• Check that all fans are spinning
• Clean dust from heatsinks and fans
• Re-apply thermal paste if the CPU is more than 3–4 years old
• Monitor temps in BIOS or with HWiNFO64 — CPU shutdown typically triggers at 95–105°C

Failing Power Supply

A power supply that can’t deliver stable voltage causes random restarts, especially under load:

• Restarts happen more during gaming, video editing, or other CPU/GPU-intensive tasks
• The system may restart instantly without any warning or blue screen
• PSU testers ($15–$25) can check voltage stability, but swapping with a known-good PSU is the most reliable test

Bad RAM

Faulty RAM causes seemingly random crashes and restarts:

• Run Windows Memory Diagnostic (search “memory” in Start menu)
• Or use MemTest86 from a USB drive for a more thorough test
• If errors are found, try removing one stick at a time to identify which module is failing

Failing Storage Drive

• Open Command Prompt as admin and run: wmic diskdrive get status
• Use CrystalDiskInfo to check SMART data — look for reallocated sectors, pending sectors, or “Caution” status
• An SSD with worn-out flash cells may cause data corruption that triggers restarts

Disable Automatic Restart on Failure

By default, Windows restarts automatically after a crash instead of showing the blue screen error message. To see the actual error:

1. Right-click This PC → Properties → Advanced system settings
2. Under Startup and Recovery, click Settings
3. Uncheck “Automatically restart”

Now the computer will show the blue screen with an error code instead of immediately restarting, which makes diagnosis much easier.