Hello, are you referring to Cortana - the search box you may see in your taskbar or at the bottom left of your start menu? ('windows search' is usually the traditional search feature in Windows explorer).
(& The Windows Search service is what does the indexing which allows things to be found fast on your PC - Cortana uses the index it creates to search 'My Stuff')
Do you have any restore points before the problem started?
What happened before the problem started? Did you make or notice any changes to your PC?
Have you made any changes to Settings, in particular to Privacy settings?
What are you looking for in the task manager.. I see this:
Can you see Cortana there?
If you open the Action Centre (the white square with 3 lines in it near the clock) is the Location tile 'on'?
Press the Windows key + R, and in the Run box, type services.msc <enter>
In the list of services, is Geolocation running?
And can you confirm your start menu opens properly?