How to Fix High CPU Usage Even When 'Nothing' Is Open

🔧Step-by-Step Fixes

Fix 1: Identify the Problem Process

First, let's figure out exactly what's using your CPU:

1. Press Ctrl + Shift + Esc to open Task Manager
2. Click the Processes tab
3. Click the CPU column to sort by usage (highest on top)
4. Look at what's using the most CPU - common culprits include "Windows Modules Installer Worker", "System", "Runtime Broker", "Windows Search", or "Antimalware Service Executable"
5. Write down the process name before trying to fix it

Note: If "System" or "System Idle Process" shows high usage, that's actually normal - it means the CPU is idle.

Fix 2: Restart Windows Search

Windows Search indexing often causes high CPU usage:

1. Press Windows + R, type services.msc, press Enter
2. Scroll down and find Windows Search
3. Right-click it and select Restart
4. If high CPU continues, right-click again and select Properties
5. Change Startup type to Manual or Disabled
6. Click Apply and OK

Disabling Windows Search means the search function will be slower, but it's worth it if this was causing your CPU problem.

Fix 3: Stop SysMain (SuperFetch)

SysMain tries to speed up your system but can actually slow it down on some computers:

1. Press Windows + X and select Terminal (Admin) or Command Prompt (Admin)
2. Type net.exe stop sysmain and press Enter
3. Check if CPU usage drops in Task Manager
4. To make this permanent, press Windows + R, type services.msc, press Enter
5. Find SysMain, right-click, select Properties
6. Change Startup type to Disabled
7. Click Apply and OK

Fix 4: Adjust Power Settings

Windows power settings can force your CPU to run at maximum speed constantly:

1. Press Windows + X and select Power Options
2. Click Additional power settings
3. Next to your current plan, click Change plan settings
4. Click Change advanced power settings
5. Expand Processor power management
6. Expand Minimum processor state
7. Set both On battery and Plugged in to 5% (default is often 100%)
8. Click Apply and OK

Fix 5: Scan for Malware

Malware and cryptominers often hide in the background eating up CPU:

1. Press Windows + I to open Settings
2. Go to Privacy & Security > Windows Security
3. Click Virus & threat protection
4. Select Scan options
5. Choose Full scan and click Scan now
6. Let the scan complete (takes 30-60 minutes)
7. Remove any threats found

Consider also running a secondary scan with Malwarebytes (free version available) for extra protection.

Fix 6: Disable Startup Programs

Too many background programs can collectively cause high CPU usage:

1. Press Ctrl + Shift + Esc to open Task Manager
2. Click the Startup tab
3. Disable programs you don't need immediately at startup
4. Right-click each unnecessary program and select Disable
5. Restart your computer

Fix 7: Update Windows and Drivers

Outdated software can cause CPU inefficiency and bugs:

1. Press Windows + I to open Settings
2. Go to Windows Update
3. Click Check for updates
4. Install all available updates
5. Click Advanced options > Optional updates
6. Install any driver updates available
7. Restart when updates complete

Fix 8: Disable Windows Tips and Notifications

This minor feature can sometimes cause CPU spikes:

1. Press Windows + I to open Settings
2. Go to System > Notifications
3. Turn off Show me tips about Windows
4. Also consider turning off Get notifications from apps and other senders for apps you don't need alerts from