How to Fix High CPU Memory Usage in Windows 10

High CPU and memory usage in Windows 10 can make your PC sluggish, freeze apps, and drain your battery. This guide walks you through practical steps to identify what’s hogging your resources and reduce the load, from simple restarts to more advanced tweaks like disabling startup programs and adjusting virtual memory.

What You’ll Need

Administrator access to your Windows 10 PC
About 15–30 minutes of time
Optional: a USB drive for creating a bootable Windows installation media (only if you plan to do a clean install as a last resort)

Step-by-Step

Restart your PC. This clears temporary memory and stops background processes that may be stuck. Save your work, then click Start > Power > Restart.
Check Task Manager for resource hogs. Press Ctrl + Shift + Esc to open Task Manager. Click “More details� at the bottom if you only see a small window. Go to the “Processes� tab and click the “CPU� and “Memory� column headers to sort by usage. Look for apps or background processes using unusually high percentages (e.g., 30% or more CPU when idle, or hundreds of MB of RAM).
End or restart problematic processes. If a non-essential app is using excessive resources, right-click it and select “End task.� If it’s a system process like “Windows Explorer� or “Antimalware Service Executable,� right-click and choose “Restart� instead.
Disable startup programs. In Task Manager, go to the “Startup� tab. Right-click any program you don’t need at boot (e.g., chat apps, updaters) and select “Disable.� This reduces background CPU and memory usage from the moment you start Windows.
Run a full virus scan. Malware can cause high CPU and memory usage. Use Windows Security (built-in) by going to Settings > Update & Security > Windows Security > Virus & threat protection > Scan options, and choose “Full scan.� Alternatively, use a trusted third-party antivirus.
Update Windows and drivers. Go to Settings > Update & Security > Windows Update and click “Check for updates.� Install all updates, including optional driver updates. Outdated drivers can cause memory leaks and CPU spikes.
Adjust for best performance. Right-click the Start button and select “System,� then click “Advanced system settings� on the right. Under “Performance,� click “Settings.� Choose “Adjust for best performance� (or customize by unchecking animations) and click OK. This reduces CPU and memory overhead from visual effects.
Increase virtual memory (page file). In the same “Performance Options� window, go to the “Advanced� tab, then under “Virtual memory� click “Change.� Uncheck “Automatically manage paging file size for all drives,� select your system drive (usually C:), choose “Custom size,� and set both Initial and Maximum size to 1.5 times your RAM amount (e.g., if you have 8 GB RAM, set both to 12288 MB). Click Set, then OK, and restart. This gives Windows more headroom when RAM is full.
Check for memory leaks in specific apps. If a particular app (like Chrome, Slack, or a game) consistently uses more memory over time, try updating it, clearing its cache, or reinstalling it. Some apps have known memory leak issues that are fixed in newer versions.
Disable unnecessary background apps. Go to Settings > Privacy > Background apps. Turn off “Let apps run in the background� or selectively disable apps you don’t need running in the background.
Run System File Checker and DISM. Open Command Prompt as administrator (right-click Start > Command Prompt (Admin)). Type sfc /scannow and press Enter. After it finishes, type DISM /Online /Cleanup-Image /RestoreHealth and press Enter. This repairs corrupted system files that can cause high resource usage.
Perform a clean boot. Type msconfig in the Start menu and open System Configuration. Go to the “Services� tab, check “Hide all Microsoft services,� then click “Disable all.� Go to the “Startup� tab and click “Open Task Manager,� then disable all startup items. Restart. If the problem goes away, re-enable services and startup items one by one to find the culprit.
Reset Windows (as a last resort). If nothing else works, go to Settings > Update & Security > Recovery > “Reset this PC.� Choose “Keep my files� to reinstall Windows while preserving your personal files, or “Remove everything� for a clean slate. This will remove apps and settings, so back up important data first.

Common Mistakes

Ending critical system processes: Ending processes like “System� or “Windows Explorer� can cause crashes or data loss. Always research a process before ending it.
Disabling all startup items blindly: Some startup items are necessary for hardware (e.g., audio drivers). Disable only what you recognize.
Setting virtual memory too high: Setting the page file to more than 2-3 times your RAM can waste disk space and slow down your PC. Stick to 1.5 times RAM as a general rule.
Ignoring malware scans: High CPU usage can be a sign of crypto-mining malware. A quick scan can save you hours of troubleshooting.

Tips

Keep your PC cool: High CPU usage can cause overheating. Clean dust from vents and ensure fans are working.
Use a lightweight antivirus: Some antivirus programs are resource-heavy. Consider using Windows Security or a lightweight third-party option.
Monitor resource usage over time: Use Task Manager’s “Performance� tab to watch CPU and memory usage trends. If memory usage creeps up over days, that’s a leak.
Close unused browser tabs: Each tab uses memory. Use an extension like OneTab to suspend inactive tabs.
Upgrade RAM if needed: If your PC has 4GB or less, adding more RAM is the most effective long-term fix for memory-related slowdowns.

Troubleshooting

If the steps above don’t reduce high CPU or memory usage, consider the following:

If the problem persists after a clean boot: The issue may be hardware-related (e.g., failing RAM or hard drive). Run Windows Memory Diagnostic (type “Windows Memory Diagnostic� in Start, choose “Restart now and check for problems�).
If a specific process keeps spiking: Search online for the process name to see if it’s a known issue. For example, “Antimalware Service Executable� can spike after updates; running a full scan manually often settles it.
If your PC freezes completely: Force a restart by holding the power button. After restarting, check the Reliability Monitor (type “reliability� in Start) to see error reports.
If you suspect malware but the scan finds nothing: Try a second opinion scanner like Malwarebytes (free version).
If Windows Update is stuck: Run the Windows Update Troubleshooter from Settings > Update & Security > Troubleshoot > Additional troubleshooters.

Frequently Asked Questions

Why is my CPU usage at 100% when idle?

This is often caused by background processes like Windows Update, antivirus scans, or a memory leak in a driver. Check Task Manager to see which process is using the CPU, and try updating drivers or disabling startup items.

How much RAM usage is normal in Windows 10?

On a fresh boot, Windows 10 typically uses 2-4 GB of RAM. If you have 8 GB or more, usage above 80% when running many apps is normal. If it’s constantly at 100% with only a few apps open, you may need more RAM or have a leak.

Can I increase RAM without buying more?

You can increase virtual memory (page file) to use disk space as RAM, but it’s much slower. It can help prevent crashes but won’t match physical RAM performance.

Is it safe to disable Superfetch (SysMain)?

Superfetch (now called SysMain) preloads frequently used apps into RAM. Disabling it can free up memory but may slow app loading. On SSDs, it’s less useful. You can disable it via Services.msc if it causes high disk or CPU usage.

Why does “System� process use high CPU?

This is often due to driver issues, especially network or storage drivers. Update your chipset, network, and storage drivers from the manufacturer’s website.

Will resetting Windows fix high memory usage?

Yes, a clean reset removes problematic apps and drivers, and fixes corrupted system files. It’s a last resort after other steps fail.

General steps for current mainstream versions; menus can differ by device and version. See the disclaimer or report an error.

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