Windows 11 might be one of the best iterations of the OS from Microsoft, but it doesn't mean that it's perfect. Problems pop up from time to time, and one such problem that has plagued countless Windows 11 users is the 100% disk usage issue.

Many users have reported that the disk usage on their Windows 11 PC goes up to 100% out of nowhere. If your Windows 11 machine feels sluggish, programs crawl, or everything seems to freeze up, it's possible you're facing this dreaded issue. Fortunately, this problem isn't without solutions. Let's get going!

Find the Reason Behind the 100% Disk Usage

Before we go on to any potential fixes for the problem, you need to find the culprit behind this issue. Often, the issue stems from a specific process or application excessively writing or reading from the disk, which can be figured out from the Task Manager.

  1. Press Ctrl + Shift + Esc to open Task Manager.
  2. Go to the Processes tab.
  1. Then, if the disk usage is at 100%, click on it.
  1. The processes with the highest disk usage will shift to the top. Identify any third-party apps that might be taking unusually high resources and end those tasks.
  2. Disk usage will start to reduce. If an app repeatedly hogs the disk, try reinstalling that app to fix it.

If you could find a third-party app with high disk usage, you don't need the rest of the fixes in this guide.

However, there's a high chance that you might not find any third-party apps, and there's no obvious reason behind 100% disk usage. In that case, follow along.

Common Reasons Behind 100% Disk Usage

There are a few things that can cause the 100% disk usage issue on your Windows 11 PC, including:

  • Outdated drivers
  • Windows services like Superfetch or Windows Search
  • Background applications
  • Malware
  • Intensive antivirus scans
  • Issues with your hard drive

Fix 100% Disk Usage in Windows 11

It's impossible to know what could be causing the mayhem on your system without some trial and error. To fix this issue on your PC, follow these troubleshooting steps.

1. Restart PC

Before you try any elaborate fixes, stick to this simple fix, especially if you're facing this issue for the first time or rather infrequently. Restarting your PC should return the disk usage to normal right away.

However, if the problem keeps popping up, then you need to try the other fixes until you find one that addresses the root cause.

2. Update Storage Drivers

Outdated device drivers, especially for your storage disks, can cause this issue.

  1. To update your storage drivers, right-click on the Start menu and select 'Device Manager' from the menu.
  1. Then, expand the section for 'Disk Drives'.
  1. Right-click on the drive and select 'Update driver' from the menu.
  1. Then, click on 'Search automatically for drivers' from the window that appears.
  1. If there are updates available for the device, Windows 11 will download and install them automatically.

Restart your PC and see if the issue was fixed.

3. Disable MSI Mode

On systems with Advanced Host Controller Interface PCI-Express (ACHD PCIe) models running the StoreAHCI.system driver, the disk usage issue can arise because of firmware incompatibility. In such cases, disabling the Message Signaled Interrupt (MSI) mode can fix the disk usage.

You can disable MSI mode by following these steps:

  1. First, open the 'Device Manager' on your system.
  2. Then, expand the 'IDE ATA/ATAPI controllers' section.
  1. Right-click on the controller that appears and select 'Properties' from the context menu.
  1. Switch to the 'Driver' tab from the Properties dialog box and click the 'Driver Details' button.
  1. If the driver details say storahci.sys in the name (ours doesn't), then you need to proceed forward. Click 'OK' to close the Driver dialog box.
  1. Now, switch to the 'Details' tab from Properties. Then, switch to 'Device Instance Path' from the drop-down menu. Copy the path and paste it somewhere handy, such as Notepad, as you'll need it in the next step. Close the device manager.

Now, follow these steps to disable MSI using Registry Editor.

Note: Registry is an important part of the Windows OS. Always create a backup before making any changes in case anything goes wrong.
  1. Press Windows + R to open the Run window.
  2. Type regedit in the run window and press Enter to open the Registry Editor.
  1. Press 'Yes' if a User Account Control dialog box appears.
  2. Navigate to the following location in the Registry Editor: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Enum\PCI
  3. Now, see the entry that you previously copied in Notepad, match it with the options under PCI, and expand the corresponding property.
  4. Then, navigate to this location: Device Parameters > Interrupt Management > MessageSignaledInterruptProperties.
  5. In the right panel, go to the 'MSISupported' option and double-click on it.
  1. Then, change the value to 0 and click 'OK'.

Close the Registry Editor and restart your PC to apply the changes. Then, check if the issue was resolved.

While Windows search is insanely helpful when you want to find any files or folders, it can sometimes malfunction and get stuck in a loop. In this case, rebuilding the search index can help.

  1. Open Windows search, type 'Indexing', and choose 'Indexing Options' from the search results.
  1. Then, go to the 'Advanced' option.
  1. Click on the 'Rebuild' button to delete and rebuild the index.
  1. Click on 'OK' to confirm.

Index rebuilding might take some time, so you'll need to be patient. Once it's complete, see if there's any improvement in disk usage.

If index rebuilding did help with disk usage, but you're back to square one once your system reboots, you will need to disable Windows search since this means there's an issue with search that's causing high disk usage on your Windows 11 PC; Index rebuilding can only help temporarily until the next system reboot.

To disable Windows search, follow these steps:

  1. Open the Run Window (Windows + R), type services.msc , and press Enter.
  2. From the Services window, go to 'Windows Search', right-click on it, and select 'Properties' from the menu.
  1. Click the 'Stop' button under 'Service Status'.
  1. Then, select 'Disabled' from the drop-down menu next to 'Startup type'.
  1. Click 'Apply and 'OK' to save the changes.

Check if the issue with the high disk usage was resolved.

5. Disable the SysMain (Superfetch) Service

SysMain (also known as Superfetch) is a Windows service that preloads your frequently used apps to RAM to improve the system performance. However, it can often hog disk space, ironically leading to reduced performance on your PC.

You can disable the SysMain service on your PC and check if it makes a difference to the 100% disk usage.

  1. Open 'Windows Services' using the Run app.
  2. Then, go to 'SysMain' from the right panel and right-click on it. Select 'Properties' from the context menu.
  1. Next, choose 'Disabled' from the drop-down menu next to Startup Type. Also, click the 'Stop' button under 'Service Status'.
  1. Click 'Apply' and 'OK' to save the changes.

If the issue is still not resolved, you can enable the service again since it's a legitimate Windows service that helps with your system's performance.

6. Disable Connected User Experience and Telemetry Service

This service can also often cause unnecessarily high disk usage on Windows PCs. It is responsible for collecting and transmitting the diagnostic data from your system to Microsoft's servers. Disabling it can significantly improve the problem.

  1. Once again, open Windows Services on your PC.
  2. Then, right-click on the 'Connected User Experiences and Telemetry' option and go to 'Properties'.
  1. Click on 'Stop' under Service status to stop the service and choose 'Disabled' from the drop-down menu next to Startup Type.
  1. Click the 'Apply' and 'OK' buttons.

7. Manage Startup Apps

If you have too many apps that load at startup when your PC boots, it can considerably slow down your PC and cause the 100% disk usage issue.

  1. Open the Task Manager on your PC.
  2. Switch to 'Startup Apps' from the options on the left.
  1. Then, disable any apps that you don't need at startup by selecting the app and clicking 'Disable'.

You can also manage startup apps from Settings > Apps > Startup Apps.

8. Check for Malware

If you still can't get rid of the issue, it's time for a malware scan to make sure that it's not a virus infecting your system and making it go haywire. You can use your preferred third-party anti-virus software or Windows Defender to check for malware.

  1. To use Windows Defender, open 'Windows Security' on your PC from the Start or Search menu.
  2. Go to 'Virus & threat protection'.
  1. Then, either do a quick scan or a full scan (preferable but takes longer) to detect and remove any possible viruses. To do a full scan, click the 'Scan options' button.
  1. Select 'Full scan' from the options and click the 'Scan now' button.

9. Reset Virtual Memory

Virtual Memory is a handy solution in Windows for virtually expanding memory at times when your PC runs out of RAM. It uses your hard disk as a swap to hold some files and programs. However, it can sometimes get damaged and take up huge disk space. Resetting the Virtual Memory will help if it's the culprit.

  1. To reset the Virtual Memory, type sysdm.cpl in the Run dialog box and press Enter.
  2. Switch to the 'Advanced' tab in the System Properties window that opens.
  3. Click the 'Settings' button in the 'Performance' section.
  1. Switch to the 'Advanced' tab and click on 'Change' in the 'Virtual Memory' section.
  1. Uncheck the option for 'Automatically manage paging file size for all drives'.
  1. Make sure that the drive where Windows is selected (C: by default) is selected. Then, select the 'Custom Size' option.
  2. In the initial size text box, enter the value that's shown in the 'Recommended' option, 1905 in our case.
  3. For maximum size, enter a value that shouldn't be more than 1.5x the size of your RAM. But you can enter a lower value, too; since we're trying to limit the disk usage, don't make this number too high.
  1. You can also select 'No paging file' if you don't want to allocate any virtual memory from your disk at all.
  1. Click on 'Set' and 'OK' to save the changes.

In case none of the above options helped, check the health of your drive. It's possible that your disk has physical damage. However, if your disk is healthy but you're using a traditional HDD drive, the issues could be stemming from that, and you might need to consider upgrading to an SSD drive.