notepad++: How to reset all the setting to default ones?

The easiest way to reset to defaults would probably be to delete the configuration files. This also means you can back them up if you ever want them back.

Notepad++ uses the follwowing path for settings using a default installation settings:

%APPDATA%\Notepad++

In that directory there are several .xml configuration files. Remove the ones you want to reset and restart Notepad++.

Go to

C:\Users\Administrator\AppData\Roaming\notepad++

(type your username instead of "Administrator" in the above path)

Delete the file "stylers.xml".

Restart Notepad++