Is there a way to recreate Windows File Explorer? Is there an API for it?

It's definitively possible, see directory opus for exemple. The window's API consist of very low level C, and you have to use that. You also need something to render UI !

This is possible in every language that can invoke dlls. Also an existing graphic framework makes things easier. You can write that too tho.

check .net's System.IO

NodeJS const fs = require('fs'); ✌

@Kimmax

This is possible in any language at all, that can read files from the system. Even Java, or Python, for example. (Though, I wouldn't recommend either for such a task. A 'C' language would be much better suited, IMO.)

@Kimmax

Actually, it would be a fun project to try and re-create the Windows Exsplorer (or just "a" Explorer) in as many languages as possible! :D

@Cyanite Actually, what I said is targeted at the windows api directly, Kernel32.dll, which is being invoked by the JRE (Java runtime environment). If you want to go lower, you would have to bypass the windows kernel. Well, good luck with that..