If your Windows 10/11 PC shows 100% CPU usage, you will experience lag, stutters, freezes, and slow performance. This is one of the most common problems in Windows, especially on low-end and mid-range PCs.

In this guide, you’ll learn why the CPU goes to 100%, how to find the cause, and how to fix it permanently using simple methods.

⭐ Why Does CPU Usage Go to 100%?

Common reasons include:

  • Background apps running
  • Windows services stuck
  • Malware or unwanted processes
  • Heavy startup programs
  • Windows Update bugs
  • Game anti-cheat services
  • Driver issues

Let’s fix this step by step.

✅ Method 1: Disable Background Apps

  1. Press Windows + I
  2. Go to Apps → Installed Apps
  3. Disable unnecessary apps running in background
  4. Remove unwanted software

🔹 This reduces CPU usage by 10–20%.

✅ Method 2: Disable “SysMain” (Superfetch)

This service causes 100% CPU on many PCs.

  1. Press Windows + R
  2. Type: services.msc
  3. Find SysMain
  4. Right-click → Stop
  5. Set Startup type → Disabled

✅ Method 3: Disable Windows Search Indexing

  1. Go to services.msc
  2. Find Windows Search
  3. Right-click → Stop
  4. Set Startup type → Disabled

This fix is highly effective on HDD systems.

✅ Method 4: End High-Usage Tasks

  1. Press CTRL + SHIFT + ESC
  2. Open Task Manager
  3. Check CPU column
  4. End tasks using too much CPU (EXCEPT system tasks)

Common culprits:

  • Google Chrome
  • GameLauncher.exe
  • Update.exe
  • RuntimeBroker

✅ Method 5: Disable Startup Programs

  1. Open Task Manager
  2. Go to Startup Apps
  3. Disable everything unnecessary
    (Spotify, Epic, Steam auto-start, Discord, etc.)

✅ Method 6: Update / Reinstall Drivers

Outdated drivers cause CPU spikes.

Use:

  • AMD Adrenalin
  • NVIDIA GeForce Experience
  • Intel Driver Support Assistant

Always keep chipset drivers updated.

✅ Method 7: Scan for Malware

  1. Open Windows Security
  2. Go to Virus & Threat Protection
  3. Full Scan

Optional (Better): Use Malwarebytes Free.

✅ Method 8: Reset Windows Update Components

If Windows Update is stuck:

  1. Open CMD as Administrator

  2. Copy & paste:

    net stop wuauserv net stop bits net stop cryptsvc ren C:\Windows\SoftwareDistribution SoftwareDistribution.old ren C:\Windows\System32\catroot2 catroot2.old net start wuauserv net start bits net start cryptsvc

This fixes update loops that cause high CPU.

⭐ Bonus: Best Power Settings

  1. Go to Control Panel → Power Options
  2. Select High Performance

This stabilizes CPU usage.

🟢 Conclusion

High CPU usage is one of the most annoying issues in Windows 10/11, but following the steps above will reduce CPU spikes and make your PC run smoother instantly.

If the issue continues, your CPU may be:

  • Overheating
  • Thermal throttling
  • Or the PC needs simple cleanup & cooling

Comment below if you need a custom fix for your PC specs!