There is a bug in a startup program called SuperFetch in Windows 10 that will pin your disk is at 100% usage and make your computer slow.
Prerequisites: Windows 10 computer, command prompt knowledge
Difficulty Level: Member • Nerd • Platypus
Estimated Time: 30min
Expected Outcome: Windows stops showing 100% disk usage when idling
Tools Required: Windows 10 PC and administrator privileges
Disable SuperFetch
SuperFetch helps to decrease boot time and make must-load programs more efficiently. However, it has been identified as a potential cause of disk performance issues in Windows 8 and later versions of Windows, including Windows 10. Here’s how to stop this service:
1) On your keyboard, press Windows logo key, type command prompt, then select Run as administrator.

2) Click Yes at the User Account Control prompt.

3) The command prompt will once again display. Type in the following command:
net.exe stop superfetch
4) Hit Enter on your keyboard.

5) If the command above isn’t valid, try the following one instead:
net.exe stop sysmain
6) Wait for a few minutes to see if your computer starts performing better. Or check your computer’s disk usage: Type “task manager” in the Windows search bar and select Task Manager, then in the Processes tab, look at the % at the top of the Disk column. If it’s no longer 100%, you’ve fixed the problem!

If the 100% disk usage problem persists, try the next method, below.