To enable the classic old legacy Search Box in Explorer on Windows 10, you can tweak the Registry or use Mach2. Do it if you do not like current default behavior.

While there is no direct or built-in way to enable the new taskbar search button in Windows 11, we can do this with the help of a free command-line tool named ViveTool.

Here’s how it works. Once you upgrade to the Windows 10 May 2019 Update (version 1903), you'll notice something different in the taskbar. You'll see a search box and a Cortana button next to it.