This is an open source software, a very nice replacement for Windows Notepad. Simply click on the Download to get the download link, at the time of this writing, the current version is 5.8.6. You can read for more information about this software at the homepage.
Run the downloaded file, as usual, Next, Next, … and the Notepad++:
It is very nice and light editor, with the code folding feature that can “fold” all the portion to make your code look nicer.