How to fix the high disk usage (100 percent) on Windows 10?

A common problem that users face in their Windows 10 system is the high CPU utilization and high disk usage, resulting in slow performance even though the system is loaded with a good hardware configuration.

If you are one of such users, facing 100% disk usages on Windows 10 system, this article will help you to troubleshoot and fix it.

How to fix the 100% disk usage on Windows 10?

If you are having 100% disk usage on your Windows 10 system, even when the system is idle, this could be due to the SuperFetch running in the background. You can troubleshoot to check whether this is the main culprit for you.

To troubleshoot, follow the steps mentioned below:

1. Open the Task Manager (CTRL + Shift + ESC) and navigate to the Performance | Disk tab.
2. Open the Command Prompt with Admin privileges.
3. Type the command net stop sysmain in the console window and press Enter to stop the SuperFetch service.
4. If you see a drastic drop in the Disk usage like below screenshot, and an improvement in the system performance, Superfetch would be the root cause.
5. To double confirm, restart the Superfetch service by entering the command net start sysmain in the console window and press Enter.
6. Now if you see high disk usage once again, as shown in the following screenshot, then Superfetch is the main issue behind 100% disk usage on your system.
7. Go back to the command prompt once again, and stop the service by entering the command net stop sysmain.
8. To stop the service permanently, go to Start, search for services.msc and open it.
9. Within the Services window, search for SysMain, right-click on that entry, and click Properties.
10. Now as shown in the following screenshot, click the Startup type dropdown and select Disabled.
11. Click on Apply | OK for the changes to take effect.

This is one of the most common issues that cause the 100% disk usage on Windows 10. But there are also some pitfalls if you disable the Superfetch. As long as you are not having any other trouble after stopping the service, keep it turned OFF. For normal usage, where it is not causing any performance issue even if the disk usage is high, keep it enable and running.