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Fix a PC that uses too much CPU

We'll identify the high-CPU process, close heavy apps, update drivers, and rule out malware—or tell you when to call a pro.

Troubleshooting · Home maintenance
15–30 min
Step 1 of 6

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Steps

Goal: Identify the high-CPU process and reduce usage by closing apps, updating drivers, or ruling out malware.

  • Open Task Manager (Ctrl+Shift+Esc) and sort by CPU. Note which process uses the most.
  • Good: Process identified. Proceed to Identify the process.
  • Bad: Unclear. Check Windows Search indexing and startup programs.

Identify the process

Goal: See what is using the CPU.

  • Press Ctrl+Shift+Esc. Click the CPU column header to sort. The top process is usually the culprit.
  • Common high-CPU processes: browser (many tabs), Windows Search (indexing), Windows Update, video apps, games.
  • Good: You know the process. Close it or follow the guide for that type.
  • Bad: System process or unknown. Disable indexing, update drivers, run malware scan.

Close apps and disable startup

Goal: Reduce CPU by closing heavy apps and startup programs.

  • Close browser tabs, video apps, and games. Task Manager > right-click process > End task if needed.
  • Task Manager > Startup tab. Disable programs you do not need at boot.
  • Good: CPU drops when apps are closed.
  • Bad: CPU stays high. Update drivers and run malware scan.

When to get help

Call a technician if:

  • CPU stays high with no identifiable process.
  • Malware scan found threats you cannot remove.
  • The PC overheats and shuts down.

Verification

  • Task Manager shows CPU usage under 20% when idle (no heavy apps open).
  • Fans run quieter when idle.
  • The PC responds normally when opening apps.

Escalation ladder

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

  1. Identify and close Task Manager—find process; close heavy apps and browser tabs.
  2. Indexing and startup Disable Windows Search indexing if culprit; disable startup programs.
  3. Drivers and malware Update Windows and graphics drivers; run malware scan.
  4. Call a pro No clear process, malware persists, or overheating.

What to capture if you need help

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

  • Process name and CPU percentage:
  • Whether closing the app reduces CPU:
  • Windows and driver update status:
  • Steps already tried:

Have you opened Task Manager and identified the high-CPU process?

Task Manager shows which process uses the most CPU.

Ctrl+Shift+Esc. Sort by CPU. Note the top process. Good: Process identified—close it or update it. Bad: Process unknown or system process—check indexing and drivers.

Yes No

You can change your answer later.

Open Task Manager

Ctrl+Shift+Esc. Click CPU column to sort. Note the process name. If it is an app you recognize, close it. If it is Search, Windows Update, or a system process, follow the guide for that case.

Done

Can you close the process or app?

Closing the app should drop CPU.

Close the app normally. If it will not close, Task Manager > right-click > End task. Good: CPU drops. Bad: Process restarts or is a system service—disable indexing or startup, update drivers.

Yes No

You can change your answer later.

Have you updated Windows and graphics drivers?

Outdated drivers often cause high CPU.

Settings > Update & Security. Device Manager > Display adapters > Update driver. Restart. Run malware scan. Good: CPU normal. Bad: Still high—call a technician.

Yes No

You can change your answer later.

CPU usage is normal

CPU usage has dropped. Consider disabling startup programs to prevent future spikes.

Done

Call a technician

No clear process, malware persists, or PC overheats. A technician can diagnose hardware or persistent malware.

Done

Reviewed by Blackbox Atlas

Frequently asked questions

Why would a PC use too much CPU?
Heavy apps (browsers, video), Windows Search indexing, malware, outdated drivers, or a stuck process. Task Manager shows which process is responsible.
Can I fix high CPU usage myself?
Yes. Close heavy apps, disable startup programs, update drivers, run a malware scan. If a specific process keeps spiking with no clear cause, a technician may help.
When should I call a technician for high CPU?
If you have closed apps and updated drivers but CPU stays high with no obvious process, or if the PC overheats and shuts down. Hardware or malware may need a pro.

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