Every app and game uses the CPU for proper execution and processing.
The CPU is one of the vital computer resources that a computer cannot work without. It is responsible for running all the software on a computer system. Different software causes different CPU usage. The maximum use of a CPU increases its usage to 100%.
It is not good for a CPU to be at 100%. It makes your computer slow. In this case, your CPU cannot execute other apps as its usage is already maximum. This much usage also causes CPU overheating. Let’s start our topic by answering the main question without further ado.
Why CPU Usage Is 100% When Nothing Is Running?
CPU usage is 100% because of antivirus scanning of your computer, task manager calculations, unnecessary background apps, virus attacks on your computer, faulty software, wrong settings of antivirus, CPU-intensive apps and games, CPU overheating, etc.
An Antivirus Scanning Your Computer As A Background App
An antivirus scanning your computer for viruses as a background app can be a reason behind your CPU usage of 100% when nothing is running. It is the case for most Windows operating system users. But other users can have the same issue if they have allowed their antivirus to scan for viruses.
Antivirus software protects your computer from malware. But some antivirus software ruins the performance of your computer, increasing your CPU usage to 100%. It happens when the frequency of scanning viruses is set to high. As a result, such antiviruses start performing scans regularly.
Task Manager Calculations
Task manager calculations cause your CPU usage to be 100%, especially when you open it. It is intelligent software that uses your CPU to calculate and gather all the hardware and software-based stats to show you. These hardware and software are part of your computer.
The Task Manager gathers and calculates different stats to show you. This stats is about all your computer’s different apps and OS services. Also, the stats about your computer’s main hardware, such as CPU, GPU, RAM, etc. Startups and App History are also included in these stats.
Unnecessary Background Apps
Unnecessary background apps can cause your CPU usage to be 100%. Your computer processor is the only hardware responsible for executing all the apps. Simply, all apps use your CPU to run properly. More apps are simultaneously running, increasing CPU usage.
The apps running in the background keep gaining the CPU occasionally. Your computer processor becomes very busy when they are more in number and scheduled individually. Usually, the multiple tabs of your web browser cause the same problem. You can easily see such apps opening your Task Manager.
A Virus Attack On Your Computer
A virus attack on your computer can cause your CPU to go to 100%. Some viruses can make your CPU very busy, consuming its power. You will notice that your other apps and games do not run smoothly anymore. It will also degrade the performance and efficiency of your computer processor.
It will not be limited to keeping your CPU busy but will also cause your CPU to overheat. As a result, You might start experiencing CPU throttling, especially when you live in a hot area, or your computer’s temperature is high. CPU overheating can easily burn out your CPU or damage its cores.
Faulty or Updating Software
A faulty or updating software can be the reason behind your CPU usage being 100%. All apps and games use your CPU to run properly. You may have opened software that has occupied your CPU for its execution or updating for some time, causing the CPU usage to be high.
To figure out such software, right-click the taskbar and select “Task Manager.” A window with multiple tabs will appear. Go to the tab named “Processes.” This tab contains all the software that your CPU is executing. In the “CPU” named column, you will find the culprit.
Wrong Settings Of Your Antivirus Software
The wrong settings of your antivirus software can cause your CPU usage to be 100%. If you have allowed your antivirus to scan your computer frequently, it can easily increase your CPU usage. It is because the antivirus uses your computer processor for scanning for viruses.
Frequent virus scans degrade the performance of your computer system. They use your computer’s vital resources, CPU, RAM, and Storage. As a result, your computer becomes slow. Your apps and games do not run smoothly anymore during scans.
CPU overheating can easily cause its users to go to 100%. Excessive heat in a CPU can cause your computer processor to initiate thermal throttling. It is a built-in mechanism to protect your CPU from overheating. It drops the power consumption and frequency of your CPU.
As a result, very less part of your CPU is available for executing apps or games. When multiple apps run on your software, your CPU usage is 100% of the time. The traditional CPU cooler, poor computer ventilation, high room temperatures, etc., can cause overheating.
CPU-Intensive Apps & Games
CPU-intensive apps and games can be the reason behind your CPU being 100%. As it is obvious from the name, CPU-intensive apps, and games highly need your computer processor for their proper execution. Your CPU usage is always high when executing such apps or games.
Usually, the settings of CPU-intensive apps and games are too high. As a result, such software increases CPU usage dramatically. More CPU usage not only degrades the performance and efficiency of your computer but also causes your processor to generate enormous amounts of heat.
Small Powered CPU & Large Apps
Your CPU usage can be high with a small powered CPU, but the apps you run are large. In this case, your CPU will use its maximum power to execute the apps or games. This phenomenon will dramatically increase your CPU usage and start overheating.
Large apps executing on a small CPU will not give your computer processor any time to take a rest. Hence, the high CPU usage and the overheating cycle will continue until you close the app or game. It can easily damage your CPU permanently.
Multithreaded software with enormous threads during its execution can increase CPU usage to 100%. Thread is a lightweight entity that consists of program instructions. The latest CPUs are designed and manufactured to execute threads.
When an app or game initializes multiple threads simultaneously, your CPU usage boosts up. As a result, other apps can hardly use your computer processor. A continuously busy CPU not only has high usage but can also overheat easily. Small-powered CPUs can damage permanently.
How Do I Fix High CPU Usage On Windows?
1. Restart Your Computer
Restarting your computer before experimenting with other options can fix high CPU usage on Windows. Restarting your computer loads your Windows operating system again from scratch. It also closes all the hidden glitchy apps running in the background.
Rebooting eliminates long-running apps that increase CPU usage. It also clears a huge amount of temporary files wasting hardware resources. We hope that the CPU usage will come down after a fresh start. It will also help you resolve input/output device-related problems.
2. End CPU-Consuming Tasks
Ending CPU-consuming tasks can help you fix the high CPU usage on Windows. The Windows operating system has a unique mechanism for this. For this, right-click on the “Taskbar” and select “Task Manager” from the menu. Now, go to the tab named “Processes.” It contains the running apps.
After this, notice the tasks that consume your CPUs more power and time. You should be able to see them in the ‘CPU” named column. Select the task and press the button saying “End Task.” Repeat this process with all unnecessary CPU-consuming apps.
3. Update Windows Drivers
Updating the drivers of your Windows operating system can fix high CPU usage on Windows. It is possible that the drivers are faulty or outdated, causing your CPU to be 100% when nothing is running. Device drivers are responsible for the proper working of all the computer hardware.
For this, press the combination of the “Windows + I” keys to open “Settings.” A window will appear where you must select the “Update & Security” option. Click the “Check for Updates” button on the next user interface. Now, Windows will update drivers if you are connected to the internet.
4. Scan For The Viruses
Scanning for viruses can fix high CPU usage on Windows. Your computer may be under attack by a virus that keeps your CPU usage 100%. Scanning for viruses will find and delete that malware for good. Windows has a built-in scanner virus that you only need to start.
Open the “Task Manager” app and type “Virus & threat protection.” You must open the app that appears with the name that you typed. When the app opens, press the button saying “Quick Scan.” Now, Windows will scan your computer for viruses and delete them individually.
5. Edit Your Computer’s Power Plans
Editing your computer’s power plans can fix high CPU usage and bring it down. You may have the wrong power plan selected for your computer. To fix this, open the “Start Menu” and type “Edit Power Plans.” Open the app and select the label saying “Change advanced power settings.”
After this, a small window named “Power Options” will appear. Open the drop-down menu and select the “Balanced” option if it is “High Performance.” Now apply the changes, press OK, and close the app. Hopefully, now your high CPU usage will be fixed.
6. Decrease The Virus Scanning Frequency Of Your Antivirus Software
You can easily prevent your CPU usage from being at 100% by decreasing your antivirus software’s virus scanning frequency. It should not be set to daily scans as it can keep your CPU busy for hours depending on the amount of data stored on your computer.
Make your antivirus less active so it does not cause you to experience your CPU usage at 100% most of the time. Once a week is enough for you if you regularly download new data from the internet. Otherwise, scanning for viruses once or twice a month is enough.
7. Let Your Task Manager Start Properly
Letting your Task Manager start properly without any disturbances is the best idea. Put simply, do not open other apps simultaneously when you have opened the Task Manager. In this case, your CPU will become busy opening both apps, simultaneously showing CPU usage at 100%.
Open the Task Manager app and wait, leaving your computer for some time. Let it gather and calculate all the stats about your hardware and software resources and appear on the screen. There are three possible reasons for this behavior. Corrupted operating system, low RAM, less powerful CPU.
8. Reinstall Windows OS
Reinstall Windows if updating and repairing your operating system is not working to fix the high CPU usage. It is the only option you have when no other option is working. New Windows will delete all of the older versions of device drivers and operating systems, and it will install the latest versions.
Installing new Windows will erase all of your data and apps stored in the Windows drive. So, making a backup of your precious data is highly recommended. Just move that data to some other drive of your storage. As far as apps and games are concerned, you will have to install them again.
Is 100% CPU Usage Bad?
Constantly 100% CPU usage is bad for your CPU. It means your CPU is continuously under pressure which can easily overheat it. A constantly overheating CPU can easily burn out within minutes. Hence, you can lose your computer processor for good if its usage is high.
In this case, you should figure out the exact reason behind your CPU being at 100%. Finding out the cause will help you eliminate the problem easily. There may be multiple reasons behind high CPU usage. You must eliminate all the reasons until the problem is fixed.
How Much CPU Usage Is Normal?
Normal CPU usage is mostly between 1% and 5%. You are not using CPU-intensive apps or games at these levels. And when you have not opened multiple tabs of your web browser. Simple tasks like typing, playing offline video, listening to audio, viewing PDFs, etc., do not increase CPU usage.
CPU usage varies depending on the purpose you use your CPU for. For example, video streaming through online platforms increases usage from 5% to 20%. Lightweight apps and games cause CPU usage to go from 15% to 30%. CPU-intensive apps and games can take CPU usage from 80% to 100%.
Restarting your computer is the easiest fix to high CPU usage, to be 100%. Rebooting will close all the hidden apps running in the background and refresh your operating system. You should update your operating system’s device drivers if it does not work. Repairing Windows will also work.
An antivirus scanning your computer for viruses can cause CPU usage to be 100%. You should reduce the frequency of virus scans to eliminate the high CPU usage. When you open the task manager, it boosts CPU usage to 100% when collecting stats about your hardware. Just let it be for some time.
Unnecessary background apps and CPU-intensive apps and games can cause your CPU usage to be 100%. You can use Windows Task Manager to close all the unnecessary background apps. Similarly, changing the settings of CPU-intensive apps and games can help you reduce high CPU usage.
Faulty software can be a reason behind CPU usage being 100%. You should uninstall such software and find a less CPU-intensive alternative. CPU overheating can cause such problems as it reduces your CPU’s operating frequency and power. You must keep your computer processor ASAP.
If your CPU usage is continuously high to go to 100%, then you should consider editing your computer’s power plans. Just bring them down from “High Performance” to “Balanced.” But if nothing works for you, reinstalling your operating system is the last option. Make sure to make a backup first.
Hey, I’m Hammad. I write for this website to help you with the IT advice about PC, RAM, CPU, Motherboard, PSU, and other PC components.
I will provide detailed guides with images, and explain step by step so you can understand the process. Check all my articles here.