If your Windows PC is stuck at 100% disk usage, it can really slow down your PC. So slow that even performing basic tasks such as opening or closing an app can leave you frustrated.
An easy way to troubleshoot a slow computer due to high disk usage is to locate and end the problematic process in Task Manager. However, more often than not, it is a legitimate Windows service acting up and causing high disk usage in Windows 11. So, let’s explore how to fix high disk usage on Windows.
How to Find the Cause of 100% Disk Usage in Windows 11
You can use the Windows Task Manager to identify what is using your disk at its 100% capacity. The Windows Task Manager offers a wealth of information about the apps and background processes eating up your system resources.
To identify the cause of 100% disk usage using the Windows Task Manager:
- Press the Win key + X to open the WinX menu.
- Here, click on Task Manager to open the app.
- In Task Manager, open the Processes tab in the left pane.
- Click on the Disk column to view and identify apps or processes with the highest disk usage.
- If you find a third-party app using all the disk resources, right-click on the process and select End task. If the issue occurs again, try to update or uninstall the app.
However, if nothing is obvious, follow the steps below to diagnose and fix 100% disk usage in Windows 11.
1. Disable MSI Mode for the Default AHCI Driver
Some Advanced Host Controller Interface PCI-Express (ACHD PCIe) models running the StoreAHCI.system driver can cause 100% disk usage issues when Message Signalled Interrupt (MSI) mode is enabled in Windows 10. A similar issue seems to have also affected some Windows 11 computers, especially if you have upgraded from Windows 10.
To fix this issue, you will need to disable MSI mode for specific devices using the Registry Editor. Fortunately, this is easy to do.
First, we need to determine if your computer is running the default AHCI driver(StorAHCI.sys):
- Press Win + R to open Run.
- Type devmgmt.msc and click OK to open Device Manager.
- In the Device Manager, expand the IDE ATA/ATAPI controllers section.
- Here, right-click on the Standard SATA AHCI Controller and select Properties.
- Open the Driver tab in the Properties dialog.
- Next, click on the Driver Details button.
- If you see Storahci.sys under the Driver section, your computer is running the default AHCI driver and may have caused the 100% disk usage issue.
- Click OK and go back to the Properties dialog.
- Next, open the Details tab.
- Click the drop-down under the Property section and select Device instance path.
- Next, copy the path under the Value section and paste it into a Notepad file.
Now that you have determined the driver type and the path, you need to disable MSI mode using the Registry Editor.
Ensure you have created a restore point and then follow the below steps:
- Press Win + R to open Run.
- Type regedit and click OK to open Registry Editor. Click Yes if prompted by User Account Control.
- In Registry Editor, navigate to the following location:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Enum\PCI\AHCI Controller Value\Device Parameters\Interrupt Management\MessageSignaledInterruptProperties
- In the above path, replace the <AHCI Controller Value> entry with the path value you noted in the Driver Properties Detail tab.
- In the right pane of messageSignaledIntru, locate and right-click on the MSI Supported DWORD value.
- Select Modify from the context menu.
- In the Value data field, type 0.
- Click OK to save the changes.
- Close Registry Editor and restart your PC.
After the restart, check if the 100% disk usage problem is resolved.
2. Disable the SysMain (Superfetch) Service
SysMain (earlier known as Superfetch or Prefetch) is a legitimate Windows service. It is designed to preload apps you frequently use to RAM to improve the system performance.
However, SysMain is often also associated with causing high disk usage in Windows computers. Fortunately, you can manually disable the service with a marginal difference to your system performance.
To disable the SysMain service:
- Press Win + R to open Run.
- Type services.msc and click OK.
- In the Services window, locate the SysMain service.
- Right-click on the service and select Properties.
- In the Properties dialog, click the drop-down for Startup type and select Disabled.
- Also, click on the Stop button to terminate the service.
- Next, click on Apply and OK to save the changes.
Open Task Manager, and you should notice an immediate reduction in disk usage.
3. Disable Connected User Experiences and Telemetry Service
Connect User Experience, and Telemetry Service manages the collection and transmission of diagnostic data to the Microsoft server. Unfortunately, the service is also known to cause high disk usage problems in Windows 11.
You can disable the Connected User Experiences and Telemetry Service to see if it helps you fix the high disk usage problem in Windows 11.
- Press Win + R, type services.msc, and click OK,
- In the Services snap-in, locate the Connected User Experiences and Telemetry service.
- Right-click on the service and select Properties.
- Next, click the Stop button and set the Startup type to Disabled.
- Click Apply and OK to save the changes.
4. Clean Up Startup Apps
Startup apps are the apps that start automatically when your computer boots. While a handy feature, too many of them can slow down your PC. Additionally, some of these may also cause a 100% disk usage issue.
To fix the problem, go through the list of startup apps and disable any unnecessary program set to launch at startup.
To disable startup apps using Task Manager:
- Right-click on the Start button and select Task Manager.
- In Task Manager, open the Startup apps tab.
- Click on the Status column to sort apps by their status.
- Select an enabled app and click the Disable button in the top right corner.
- Do this for all the enabled apps.
Once done, restart your PC and check if the issue persists. If not, enable all the startup apps one by one till you find the conflicting app. Uninstall the app to see if that helps you eliminate the 100 percent disk usage problem in Windows 11.
5. Rebuild Search Index
The Windows search indexing helps you find files and email messages faster. While a handy tool, a malfunctioning search indexing can cause a 100% disk usage issue in Windows 11.
To fix the problem, you can rebuild the search index. This will recreate the database and resolve any issues with the index.
To rebuild the Windows search index:
- Press the Win key and type indexing.
- From the search result, click on Indexing options.
- In the Indexing options dialog, click on the Advanced button.
- Next, click the Rebuild button. This will delete and rebuild the index.
- Click OK to confirm the action.
The index rebuilding process may take some time to complete. So wait for the process to complete and then check for any improvements.
6. Disable Windows Search
If rebuilding search indexing helps but the issue reoccurs, try to disable the Windows Search service completely. Note that doing so will affect Windows search functionality on your PC.
To disable the Windows Search service:
- Press Win + R to open Run.
- Type services.msc and click OK.
- In the Services window, double-click on the Windows Search service to open its Properties.
- In the Properties dialog, click the Stop button.
- Next, set the Startup type to Disabled.
- Click Apply and OK to save the changes.
7. Turn Off Hibernation
Hibernation helps your system boot faster after a restart. However, if your PC shows 100% disk usage just after the restart, turning off Hibernation can help.
To turn off hibernation in Windows 11:
- Press the Win key and type cmd.
- Right-click on Command Prompt and select Run as administrator.
- In the Command Prompt window, type the following command and press Enter:
powercfg hibernate off
- Once executed, close the Command Prompt window.
- Open the Task Manager and check if the high disk usage issue is resolved.
8. Run a Malware Scan
If the issue persists, check your computer for malware infection. Even if you have an active Antivirus installed, a manual scan can help you detect anything malicious that may have sneaked in.
If you don’t have a third-party antivirus installed, you can perform a full scan using Windows Security. Here’s how to do it.
- Press Win + I to open Settings.
- In the left pane, open the Privacy & security tab.
- Next, click on Windows Security.
- Click on Virus and threat protection,
- Click on Scan options under Quick scan.
- Select the Full option and then click on Scan now.
A full scan takes longer than a quick scan. However, it should find any hidden malicious files and clean them for good.
While Windows Security offers excellent protection, take a second opinion with third-party antivirus for Windows 11.
Switch to Solid State Drive (SSD)
The 100% disk usage issue on some computers can be due to the traditional mechanical hard drive (HDD) or the hybrid drive itself. If feasible, consider adding a solid-state drive (SSD) to your computer and use it as a boot drive to install Windows.
SSDs are less prone to the 100% disk usage issue and can greatly improve your system performance as well.