As shown below, there is a hint in the setup "Disable Cortana by Company policy", and this problem occurs only if you set the Group Policy-User Configuration to resolve it.
Problem resolution Steps
1, press win+r key combination in the picture shown pop-up run box copy "Gpedit.msc" and then enter, you can open the computer's "Group Policy" as follows;
2, then we open into the Group Policy after we find "User Configuration"-"Management template"--"Windows components"--"File Explorer", locate the "close the display of recent search entries in the File Explorer search box" for details, as shown in the following illustration;
3, double click to enter, if the above has been checked as "Not configured", please tick "disabled", or check "Not Configured", and the end of the determination.
4, after the modification, restart the computer can be resolved.
Remember that you must refer to the above methods can be solved, of course, there are some problems can also refer to this category to find out why and repair.