Then click to open this program in the column above:

Open the window again, expand Administrative Templates in User Configuration, and then expand Windows Components inside:

Then open Window Explorer in Windows Components:

Then see this option on the right side of the open window Explorer, find "Turn off the display of recent search items in the search box of Windows Explorer", and then double-click to open:

Then cancel the default "Not Configured" in the editing page, select "Disabled" and click OK: