This article explains how to disable the Windows 10 Superfetch service if you feel that it is making your PC slow and less responsive.
How to Disable Superfetch / SysMain in Windows 10
The Superfetch feature can be enabled and disabled through the Windows Services interface.
The Windows Run dialog should now be visible, usually in the lower left corner of your screen. Type services.msc into the field provided and select OK.
The Services interface should appear, overlaying your desktop and open application windows. Find Superfetch, located on the right side of the window in the alphabetical list of services.