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Fix a desktop that restarts randomly

We'll rule out power supply, overheating, RAM, and drivers, then isolate the cause—PSU failure, thermal shutdown, faulty RAM, or driver bug—or tell you when to call a pro.

Troubleshooting · Home maintenance
15–45 min
What you'll need
  • Compressed air (for cleaning dust)
  • Temperature monitoring tool (HWiNFO, Open Hardware Monitor—optional)
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Steps

Goal: Rule out power supply, overheating, and RAM, then isolate the cause.

  • Check power cables are firmly connected. Check CPU and GPU temperatures.
  • Good: Power and temps OK. Proceed to Check power and temperatures.
  • Bad: Reseat cables, clean dust from fans.

Check power and temperatures

Goal: Rule out PSU and thermal shutdown.

  • Confirm 24-pin and CPU power cables are seated. Check PSU wattage meets system needs. Use HWiNFO to check temps—if over 85°C under load, clean dust.
  • Good: Connections secure, temps normal. Proceed to Run memory diagnostic.
  • Bad: PSU old or underpowered—may need replacement. Call a technician.

Run memory diagnostic

Goal: Rule out faulty RAM.

  • Run Windows Memory Diagnostic. Restart when prompted. If it reports errors, a RAM stick may be failing.
  • Good: Test passes. Update drivers, check Event Viewer.
  • Bad: Memory errors—call a technician for RAM replacement.

When to get help

Call a technician if:

  • Windows Memory Diagnostic reports errors—RAM may be failing.
  • The PSU is suspected faulty (old, underpowered, or making noise).
  • You have updated drivers, cleaned dust, and the desktop still restarts.

Verification

  • The desktop runs without unexpected restarts.
  • Power cables are firmly connected.
  • CPU and GPU temperatures stay under 85°C under load.
  • No memory errors from Windows Memory Diagnostic.

Escalation ladder

Work from the device outward. Stop when the problem is fixed.

  1. Power and temps Check PSU connections; check CPU/GPU temperatures; clean dust.
  2. Memory and drivers Run Windows Memory Diagnostic; update graphics and chipset drivers.
  3. Event Viewer Check Event Viewer for restart cause; disable auto-restart to see stop code.
  4. Call a pro Memory errors, PSU faulty, or software fixes did not help.

What to capture if you need help

Before calling support or posting for help, have these ready. It speeds everything up.

  • Desktop model and PSU wattage:
  • CPU and GPU temperatures when restart occurs:
  • Memory Diagnostic results (errors or pass):
  • Event Viewer Critical errors around restart time:
  • Steps already tried:

Are power cables firmly connected and temperatures normal?

Loose power and overheating are common causes of random restarts.

Check 24-pin and CPU power cables. Check CPU/GPU temps with HWiNFO. Good: connections secure, temps under 85°C—run memory diagnostic. Bad: loose cables or high temps—reseat cables, clean dust.

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Reseat power cables and clean dust

Power off, unplug. Reseat 24-pin and CPU power. Clean dust from CPU heatsink, GPU fan, case fans. If PSU is old (5+ years) or underpowered, it may need replacement—call a technician.

Done

Does Windows Memory Diagnostic report errors?

Faulty RAM causes random restarts.

Run Windows Memory Diagnostic. Errors: RAM may be failing—call a technician for replacement. Pass: update drivers, check Event Viewer. If restarts persist, PSU may be failing.

Pass Errors

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Update drivers and check Event Viewer

Update graphics and chipset drivers. Check Event Viewer for Critical errors. Disable auto-restart to see stop code if blue screen. If restarts persist, PSU replacement may be needed—call a technician.

Done

Call a technician

Memory diagnostic reported errors—RAM replacement needed. Or PSU suspected faulty. Do not replace PSU unless experienced—risk of electric shock.

Done

Reviewed by Blackbox Atlas

Frequently asked questions

Why would a desktop restart randomly?
Failing power supply, overheating (thermal protection), faulty RAM, driver bugs, or Windows updates. Check PSU connections and temperatures first.
Can I fix a desktop that restarts randomly myself?
Yes. Check PSU connections, clean dust from fans, run memory diagnostic, update drivers. Replacing the PSU or RAM may need a technician.
When should I call a technician for random restarts?
If memory diagnostic reports errors, the PSU is suspected faulty, or you have ruled out software and the desktop still restarts. PSU or RAM replacement may require a professional.

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