Ah, I misread post# 1.
Search from the desktop? Do you mean the search in File Explorer? If that is the case, try michaelrule4's suggestion - rebuild the index. There was also an issue in Win7, I think, that if Libraries (related to the index) are removed, search fails to work - does nothing. Try Restore default Libraries (in the navigation pane of File Explorer, right click on Libraries - select option).
Windows - MS Search in cCleaner has been there as long as I can remember, at least since I moved to Win8.1 (but memory being what it is ... ). It's the search cache. You can right click on any of the categories to see the files and investigate if warranted, or de-select that category and analyze again if you do NOT want to clean up the files.
edit: I read post#1 again and saw button - so that takes me back to Cortana (taskbar search button).
I'm very confused
See if you can clear it up for me by right clicking on the taskbar and see what Search option is set - try selecting Show search box - that will help me understand what search isn't working and maybe .... maybe get me on the correct path to offer some meaningful feedback. You also have to de-select taskbar properties -> Taskbar tab -> Use small taskbar buttons to see the search box !
Never mind - this doesn't work - I cannot get the search box to display on the taskbar, not matter where I set it (taskbar context menu: search, or taskbar properties -> Toolbars tab ->Search on the taskbar [ options dropdown list ]
If you want a search icon on the desktop (a shorctut to the Modern search, navigate to
and copy the search shortcut to your desktop.
There are too many searches at the moment and they're all in flux.