How to diagnose and reduce high CPU usage on Windows 10/11

Summary

This guide helps you troubleshoot and resolve: How to diagnose and reduce high CPU usage on Windows 10/11. Follow the steps below to fix the issue.

Common Causes

High CPU usage can slow your PC, cause applications to freeze, and make everyday tasks feel sluggish. This guide walks you through identifying the processes or services that are consuming excessive CPU on Windows 10 or Windows 11, and provides practical steps to reduce the load and restore smooth performance.

Quick Fix Steps

1. Save any open work and restart your computer. A fresh boot often clears temporary spikes.
2. Open Task Manager (Ctrl+Shift+Esc) and click the CPU column to sort processes by usage.
3. Right-click any process using more than 20% CPU and select End task. Only close processes you recognise; system-critical tasks should be left alone.
4. Disable unnecessary startup programs:
   1. In Task Manager, go to the Startup tab.
   2. Select each unwanted entry and click Disable.
5. Run Windows Update to ensure you have the latest fixes:
   1. Open Settings (Win+I).
   2. Navigate to Windows Update (Windows 11) or Update & Security > Windows Update (Windows 10).
   3. Click Check for updates and install any pending updates.

Detailed Instructions

1. Identify the CPU-Hogging Process

1. Open Task Manager (Ctrl+Shift+Esc).
2. Click the Processes tab.
3. Click the CPU column header to sort processes by usage percentage.
4. Note the name of any process consistently above 20%.

2. Adjust Power Settings

1. Open Control Panel and select Power Options.
2. Choose the Balanced power plan.
3. Avoid manually lowering the minimum processor state below default values, as this can cause performance issues and does not reliably reduce high CPU usage.

3. Disable Unnecessary Background Services

1. Press Win+R, type services.msc and press Enter.
2. Locate services that can be CPU-intensive, such as:
   • Windows Search
   • Superfetch (SysMain)
   • Background Intelligent Transfer Service (BITS)
3. For each service you do not need:
   1. Right-click the service and select Properties.
   2. Set Startup type to Manual.
   3. Click Stop if the service is currently running, then click OK.

4. Update Device Drivers

1. Open Device Manager (Win+X > Device Manager).
2. Expand Processors and any other category with a yellow warning icon.
3. Right-click each device and choose Update driver > Search automatically for drivers.
4. Restart the PC after updates are applied.

5. Scan for Malware and Unwanted Software

1. Open the Windows Security app directly from the Start menu.
2. Select Virus & threat protection.
3. Click Quick scan. For a deeper check, choose Full scan.
4. Consider a reputable third-party scanner (e.g., Malwarebytes) for a second opinion.

6. Reduce Visual Effects

1. Press Win+R, type sysdm.cpl and press Enter.
2. Switch to the Advanced tab and click Settings under Performance.
3. Select Adjust for best performance, or manually uncheck effects such as Animate windows when minimizing and maximizing and Show shadows under windows.
4. Click Apply then OK.

Troubleshooting

Overheating and Thermal Throttling

• Check that vents are not blocked and that fans are running.
• Clean dust from intake and exhaust grilles using compressed air.
• Ensure the computer is on a hard, flat surface with adequate airflow.
• If the chassis feels excessively hot or fans run constantly at high speed, thermal throttling may be reducing performance. Contact support for hardware inspection.

Failing Hardware

• Failing storage devices or faulty RAM can cause high system CPU usage.
• Run hardware diagnostics provided by your device manufacturer.
• If you notice frequent crashes, blue screens, or data loss, seek professional assistance immediately.

Specific Applications: Browsers and Outlook

• Web browsers: Close unused tabs and extensions. Use the browser's built-in task manager (e.g., Shift+Esc in Chrome or Edge) to identify heavy tabs.
• Microsoft Outlook: Large mailboxes or problematic add-ins can cause high CPU. Try starting Outlook in safe mode or repairing the Office installation via Control Panel > Programs & Features.

Persistent High CPU After Windows Updates

1. Boot into Safe Mode: open the Start menu, click Power, hold down Shift, and select Restart. Then navigate to Troubleshoot > Advanced options > Startup Settings > Restart and press 4.
2. If CPU usage is normal in Safe Mode, a third-party driver or service is likely the cause.
3. Roll back recent driver updates via Device Manager > Properties > Driver > Roll Back Driver.

Specific Services Known to Spike CPU

• Windows Search – Re-indexing can temporarily use a lot of CPU. To rebuild the index:
  1. Open Control Panel > Indexing Options.
  2. Click Advanced > Rebuild.
• Superfetch (SysMain) – Set to Manual as described in the “Disable Unnecessary Background Services” section.
• Windows Update – If the wuauclt.exe process is stuck, stop the Windows Update service in services.msc, delete the contents of C:\Windows\SoftwareDistribution\Download, then restart the service.

Using Performance Monitor for Advanced Analysis

1. Press Win+R, type perfmon.msc and press Enter.
2. In the left pane, expand Data Collector Sets > System and double-click System Performance.
3. Click Start. After a few minutes, stop the collection and review the Report for processes with high Processor Time.

When to Seek Further Assistance

• If CPU usage remains above 80% even after applying the steps above.
• If you notice frequent crashes, blue screens, or data loss.
• For complex hardware-related issues (e.g., failing CPU or overheating).

If you need personalized help, please Open a Ticket. Our support engineers will investigate further.

Related Articles

• Computer running slow
• Browser not loading pages
• Applications freezing or crashing

Still Having Issues?