If your laptop fan sounds like a jet engine and everything takes forever to respond, you are probably dealing with the same problem this guide solves: How to Fix Windows 11 High CPU Usage. High CPU usage means your processor is running near 100% even when you are not doing anything demanding, and the result is slow performance, overheating, and apps that freeze for no obvious reason.
The good news is that most causes are easy to identify and fix with tools already built into Windows. Below you will learn how to find the process eating your CPU, work through the fixes in order of impact, and keep the problem from coming back. No third-party “optimizer” software required.
Quick Answer
To fix high CPU usage on Windows 11, open Task Manager with Ctrl + Shift + Esc, sort the Processes tab by CPU, and note which program sits at the top. Then work through the fixes that match the cause: restart your PC, install pending Windows updates, disable unnecessary startup apps, limit background apps, run a malware scan, update your drivers, and switch your power mode to Best performance. If usage is still pinned at 100% after all of this, a Windows reset or repair is the next step.
How to Find What’s Causing High CPU Usage
Before changing anything, spend two minutes identifying the culprit. Guessing wastes time and can lead you to disable something you actually need.
- Press Ctrl + Shift + Esc to open Task Manager.
- Click Processes and click the CPU column header so the heaviest processes sort to the top.
- Watch for a minute or two. Brief spikes to 90-100% when opening a program are normal; a process that holds the CPU at high usage for several minutes straight is the problem.
- Click the Performance tab and open Resource Monitor (button at the bottom) if you want a per-process breakdown over time.
Common names that legitimately use CPU for short bursts include System, Antimalware Service Executable (Windows Security scanning in the background), and Windows Modules Installer Worker (installing updates). These usually settle down on their own. The troublemakers tend to be:
- A browser tab or app stuck in a loop (Chrome and Edge are frequent offenders)
- An outdated or buggy device driver
- Malware quietly running in the background
- A Windows service misbehaving after an update
- Too many programs launching at startup and never closing
If your CPU is high mostly right after you switch the PC on, the cause is probably startup apps — in which case you may also want to read our guide on how to fix Windows 11 slow startup, since the two problems share the same roots.
How to Fix Windows 11 High CPU Usage: Step-by-Step Solutions
Work through these in order. Most people find the problem resolves somewhere around step four or five.
1. Restart your PC and install updates
It sounds too simple, but a restart closes runaway processes, stuck services, and updates waiting to finish installing. Many “mystery” CPU spikes are just an update installer or a crashed app that never released the processor. After restarting, go to Settings > Windows Update > Check for updates and install everything offered, including optional driver updates under Advanced options. Microsoft’s own performance guidance lists outdated software among the top causes of a slow PC, and keeping current is the single cheapest fix available — more detail is on the Microsoft Support page for improving PC performance.
2. End the offending process
If Task Manager shows one specific program hogging the CPU — say, a browser, a game launcher, or an app you installed — right-click it and choose End task. This is a temporary fix, but it instantly confirms the diagnosis: if CPU usage drops back to a calm 5-15%, you found the cause. Next, check whether that app has an update available or a setting that reduces its background activity.
3. Disable unnecessary startup apps
Every program that launches with Windows takes a slice of CPU from the moment you log in. To trim them:
- Open Task Manager with Ctrl + Shift + Esc and go to the Startup apps tab.
- Look at the Startup impact column.
- Right-click anything marked High that you do not need immediately (chat apps, music players, game launchers, auto-updaters) and choose Disable.
The app still works when you open it manually — it just stops loading itself at boot. Keep your antivirus and any work-critical tools enabled. High CPU and high memory use often travel together, so if your PC also feels starved of RAM, see how to fix Windows 11 high RAM usage.
4. Limit background apps
Windows 11 lets many apps keep running in the background even when their windows are closed. Go to Settings > Apps > Installed apps, click the three dots next to an app, choose Advanced options, and set Background apps permissions to Never for anything you do not need running constantly. This is especially effective on laptops with modest processors.
5. Run a malware scan
Malware is one of the few causes of high CPU usage that you cannot afford to ignore — crypto miners and spyware are designed to consume your processor silently. Run a full scan with the built-in Windows Security:
- Go to Settings > Privacy & security > Windows Security > Virus & threat protection.
- Choose Scan options > Full scan and let it run.
If Windows Security finds nothing but the high usage persists, consider a second opinion from a reputable on-demand scanner. Do not run two real-time antivirus products at once — they will fight each other and push CPU usage even higher.
6. Update your drivers
Buggy drivers, especially for graphics cards, network adapters, and chipsets, can spin the CPU with constant error retries. The safest route is Settings > Windows Update > Advanced options > Optional updates, which offers driver updates Microsoft has validated for your hardware. For gaming PCs, the GPU maker’s own updater is also worth running.
7. Turn off the Runtime Broker hogs (one at a time)
Runtime Broker is a legitimate Windows process that manages app permissions, but it sometimes gets stuck at high CPU after an app misbehaves. If it is the top consumer in Task Manager, try this: go to Settings > System > Notifications and turn off Suggestions and tips, then go to Settings > Privacy & security and review which apps have background permissions. In most cases the broker settles within minutes.
8. Switch to the Best performance power plan
On laptops, the Balanced power mode sometimes causes the CPU to boost aggressively and inefficiently. Go to Settings > System > Power & battery and set Power mode to Best performance while plugged in. (On battery, Best power efficiency is usually the better trade-off.) Desktop users can also open the classic Power Options and select the High performance plan if it is available.
9. Reduce visual effects
Animations and transparency are handled mostly by the GPU, but on older machines they add overhead. Press the Windows key, search for Adjust the appearance and performance of Windows, and choose Adjust for best performance — or keep the few effects you like and disable the rest. This is a minor fix, but it helps on low-end hardware.
10. Repair system files with SFC and DISM
If a core Windows component is corrupted, no amount of closing apps will help. Open Terminal (Admin) from the Start menu’s right-click menu and run these two commands, one after the other:
DISM /Online /Cleanup-Image /RestoreHealth— repairs the Windows system image (needs internet).sfc /scannow— scans and repairs protected system files.
Restart afterwards. If Task Manager shows System or System interrupts as the top CPU consumer, this step fixes it more often than anything else.
11. Reset Windows as a last resort
When you have worked through everything and the CPU is still pinned at 100%, a repair install is the cleanest option. Go to Settings > System > Recovery and choose Reset this PC, keeping your files. Newer Windows 11 builds also offer Fix problems using Windows Update under Recovery, which reinstalls the current version without touching your apps or files. Back up important data first either way — it takes minutes and removes all risk.
When High CPU Usage Points to a Bigger Problem
Most spikes are software issues, but a few hardware warning signs deserve attention:
| Sign | What it likely means | What to do |
|---|---|---|
| CPU at 100% and the PC is very hot | Failing fan or dried thermal paste | Clean the vents, check fan noise, get it serviced |
| Spikes started right after a Windows update | Buggy update or incompatible driver | Install the next update, roll back the driver |
| Only happens with one specific program | That app is buggy or misconfigured | Update, reinstall, or replace the app |
| High CPU plus the PC freezes randomly | Unstable system, possibly driver or hardware | Run SFC/DISM to repair the system files |
Frequently Asked Questions (FAQs)
Is 100% CPU usage bad for my computer?
Short bursts at 100% are normal when launching heavy programs or installing updates. What is bad is sustained 90-100% usage for long periods: it generates heat, drains a laptop battery fast, makes everything else sluggish, and over time can shorten the life of cooling components. If idle usage sits above 30-40% with nothing open, something needs fixing.
What is a normal CPU usage for Windows 11 when idle?
On a healthy system with nothing demanding open, idle CPU usage usually sits between 2% and 15%. Background tasks like indexing or a security scan can push it higher temporarily. Consistent usage above 30% at idle is worth investigating with the steps in this guide.
Why is Antimalware Service Executable using so much CPU?
That process is Windows Security doing its job — usually a scheduled scan or a real-time scan of files you just opened or downloaded. It typically settles within 10-30 minutes. If it runs hot for hours every day, schedule full scans for times you are not using the PC (Windows Security > Virus & threat protection > Manage settings is not where the schedule lives; use Task Scheduler > Microsoft > Windows > Windows Defender), and make sure you are not running a second antivirus at the same time.
Can a virus cause high CPU usage in Windows 11?
Yes — crypto-mining malware and some spyware are specifically built to consume CPU while hiding from the user. If usage is high with no visible program responsible, run a full Windows Security scan and consider a second-opinion scan. Keep Windows updated so known vulnerabilities stay patched.
Will disabling SysMain (Superfetch) lower CPU usage?
SysMain mostly affects disk usage rather than CPU, but on some systems it does add processor overhead while preloading apps. If your disk is also pinned at 100%, disabling it can help — see our companion guide on fixing high disk usage for the steps. Otherwise, leave it enabled; it genuinely speeds up app launches on most PCs.
Should I use a third-party CPU optimizer or “booster” app?
No. These apps rarely do anything Windows cannot do itself, and some are bundled with adware or make aggressive registry changes that cause new problems. Everything in this guide uses built-in Windows tools, which are safer and free.
The Bottom Line
Fixing Windows 11 high CPU usage is mostly a matter of finding the process responsible and applying the matching fix: restart and update first, trim startup and background apps, scan for malware, update drivers, and repair system files if a Windows component is at fault. In the majority of cases the whole job takes under an hour and needs no new software. If nothing works and the heat and noise continue, back up your files and use the built-in Reset option — a clean Windows almost always returns CPU usage to normal. And if high CPU comes paired with a drive that is constantly maxed out, tackle that next with our guide on how to fix Windows 11 high disk usage, since the two issues often share the same cause.
Last Updated: 8 October 2026
About the author: Zaviyar Sultan is a UAE-focused writer at Paxi, covering driving, visas, banking, insurance and everyday UAE life. His guides are researched from official UAE government and regulator sources and updated regularly.
Paxi is an independent informational website, not affiliated with the UAE government or any agency mentioned; content is general information only, not legal, immigration or financial advice; verify critical details with official sources before acting.