Random restarts usually come from overheating, power problems, a crashing driver, or Windows Update restarting automatically. A restart loop at startup often follows a failed update. Turning off automatic restart on failure lets you see the error behind it.
Common causes
Windows Update restarts
Updates can restart the computer outside of active hours if not managed.
Overheating
Computers shut down to protect themselves when too hot.
Power supply or battery problems
A failing power supply or laptop battery can cause sudden restarts.
Driver crashes
A crashing driver triggers a blue screen and automatic restart, sometimes too fast to see.
Failed update
A broken update can leave Windows in a restart loop.
How to fix it, step by step
- 1
Turn off automatic restart on failure
In System > Advanced system settings > Startup and Recovery, uncheck "Automatically restart" so you can see any error.
- 2
Set active hours
In Windows Update settings, set active hours to your work hours to prevent mid-day update restarts.
- 3
Check temperatures and vents
Clean dust from vents and make sure laptops aren't used on soft surfaces.
- 4
Check Reliability Monitor
Search for "Reliability Monitor" to see crashes and errors around each restart.
- 5
Use Startup Repair for loops
If Windows won't start, use Advanced startup to run Startup Repair or uninstall the latest update.
When to call a technician
If restarts continue after these steps, it may be hardware. We'll diagnose it, protect your data, and manage updates across your office so they don't interrupt work.
On-site support across Orange County · see our IT support, managed IT, Microsoft 365 support and cybersecurity services.
Frequently asked questions
Why does my computer restart at night or over lunch?
Most likely Windows Update installing updates outside your active hours.
Can a bad power strip cause restarts?
Yes. A failing power strip or loose connection can cause desktops to reboot.
How do I get out of a restart loop?
Interrupt startup three times to reach Windows Recovery, then use Startup Repair, System Restore, or uninstall the latest update.