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
Press Windows + I
Go to Apps → Installed Apps
Disable unnecessary apps running in background
Remove unwanted software
🔹 This reduces CPU usage by 10–20%.
✅ Method 2: Disable “SysMain” (Superfetch)
This service causes 100% CPU on many PCs.
Press Windows + R
Type:
services.mscFind SysMain
Right-click → Stop
Set Startup type → Disabled
✅ Method 3: Disable Windows Search Indexing
Go to services.msc
Find Windows Search
Right-click → Stop
Set Startup type → Disabled
This fix is highly effective on HDD systems.
✅ Method 4: End High-Usage Tasks
Press CTRL + SHIFT + ESC
Open Task Manager
Check CPU column
End tasks using too much CPU (EXCEPT system tasks)
Common culprits:
Google Chrome
GameLauncher.exe
Update.exe
RuntimeBroker
✅ Method 5: Disable Startup Programs
Open Task Manager
Go to Startup Apps
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Outdated drivers cause CPU spikes.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
Open Windows Security
Go to Virus & Threat Protection
Full Scan
Optional (Better): Use Malwarebytes Free.
✅ Method 8: Reset Windows Update Components
If Windows Update is stuck:
Open CMD as Administrator
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
Go to Control Panel → Power Options
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!